We report a type-Ⅱ InAs/GaSb superlattice three-color infrared detector for mid-wave （MW）, long-wave （LW）, and very long-wave （VLW） detections. The detector structure consists of three contacts of NIPIN archite...We report a type-Ⅱ InAs/GaSb superlattice three-color infrared detector for mid-wave （MW）, long-wave （LW）, and very long-wave （VLW） detections. The detector structure consists of three contacts of NIPIN architecture for MW and LW detections, and hetero-junction NIP architecture for VLW detection. It is found that the spectral crosstalks can be significantly reduced by controlling the minority carriers transport via doping beryllium in the two active regions of NIPIN section. The crosstalk detection at MW, LW, and VLW signals are achieved by selecting the bias voltages on the device. At 77K, the cutoff wavelengths of the three-color detection are 5.3μm （at OmV）, 141μm （at 300mV） and 19μm （at -20mV） with the detectivities of 4.6xlO11 cm.Hzl/ZW-1, 2.3×10^10 cm.Hzl/2W-1, and 1.0×10^10cm.Hzl/2W-1 for MW, LW and VLW. The crosstalks of the MW channel, LW channel, and VLW channel are almost 0, 0.25, and 0.6, respectively.展开更多
A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15...A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 μm, at 77 K.A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of-20 mV, yielding a peak specific detectivity of 5.89×10^10cm·Hz^1/2·W^-1. The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK.展开更多
The eight-band κ·p model is used to establish the energy band structure model of the type-II InAs/GaSb superlattice detectors with a cut-off wavelength of 10.5μm,and the best composition of M-structure in this ...The eight-band κ·p model is used to establish the energy band structure model of the type-II InAs/GaSb superlattice detectors with a cut-off wavelength of 10.5μm,and the best composition of M-structure in this type of device is calculated theoretically.In addition,we have also experimented on the devices designed with the best performance to investigate the effect of the active region p-type doping temperature on the quantum efficiency of the device.The results show that the modest active region doping temperature(Be:760℃)can improve the quantum efficiency of the device with the best performance,while excessive doping(Be:>760℃)is not conducive to improving the photo response.With the best designed structure and an appropriate doping concentration,a maximum quantum efficiency of 45% is achieved with a resistance-area product of 688?·cm^2,corresponding to a maximum detectivity of 7.35×10^11cm·Hz^1/2/W.展开更多
In this paper we focused on the mask technology of inductively coupled plasma（ICP） etching for the mesa fabrication of infrared focal plane arrays（FPA）.By using the SiO_2 mask,the mesa has higher graphics transfer...In this paper we focused on the mask technology of inductively coupled plasma（ICP） etching for the mesa fabrication of infrared focal plane arrays（FPA）.By using the SiO_2 mask,the mesa has higher graphics transfer accuracy and creates less micro-ripples in sidewalls.Comparing the IV characterization of detectors by using two different masks,the detector using the SiO_2 hard mask has the R_0A of 9.7×10~6 Ω·cm^2,while the detector using the photoresist mask has the R_0A of3.2 × 10~2 Ω·cm^2 in 77 K.After that we focused on the method of removing the remaining SiO_2 after mesa etching.The dry ICP etching and chemical buffer oxide etcher（BOE） based on HF and NH4 F are used in this part.Detectors using BOE only have closer R_0A to that using the combining method,but it leads to gaps on mesas because of the corrosion on AlSb layer by BOE.We finally choose the combining method and fabricated the 640×512 FPA.The FPA with cutoff wavelength of 4.8 μm has the average R_0A of 6.13 × 10~9 Ω·cm^2 and the average detectivity of 4.51 × 10~9 cm·Hz^（1/2）.W^（-1）at 77 K.The FPA has good uniformity with the bad dots rate of 1.21%and the noise equivalent temperature difference（NEDT） of 22.9 mK operating at 77 K.展开更多
A long-/long-wave dual-color detector with N-M-π-B-π-M-N structure was developed based on a type-Ⅱ InAs/GaSb superlattice. The saturated responsivity was achieved under low bias voltage for both channels. The devic...A long-/long-wave dual-color detector with N-M-π-B-π-M-N structure was developed based on a type-Ⅱ InAs/GaSb superlattice. The saturated responsivity was achieved under low bias voltage for both channels. The device could be operated as a single detector for sequential detection and showed high quantum efficiencies. The peak quantum efficiencies of long-wavelength infrared band-1(blue channel) and long-wavelength infrared band-2(red channel) were 44% at 6.3 μm under 20 mV and 57% at 9.1 μm under-60 mV, respectively. The optical performance for each channel was achieved using a 2 μm thickness absorber. Due to the high QE, the specific detectivities of the blue and red channels reached5.0×10^(11) cm·Hz^(1/2)/W at 6.8 μm and 3.1×10^(11) cm·Hz1^(1/2)/W at 9.1 μm, respectively, at 77 K.展开更多
The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solu...The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solution(citric acid,phosphoric acid,hydrogen peroxide,deionized water),the best solution ratio is obtained.After comparing different passivation materials such as sulfide+SiO_(2),Al_(2)O_(3),Si_(3)N_(4) and SU8,it is found that SU8 passivation can reduce the dark current of the device to a greater degree.Combining this wet etching and SU8 passivation,the of VLWIR detector with a mesa diameter of 500μm is about 3.6Ω·cm^(2) at 77 K.展开更多
we report n Bn photodetectors based on In As0.91 Sb0.09 with a 100% cut-off wavelength of 4.75 μm at 300 K. The band of an n Bn detector is similar to that of a standard pin detector, but there is special wide bandga...we report n Bn photodetectors based on In As0.91 Sb0.09 with a 100% cut-off wavelength of 4.75 μm at 300 K. The band of an n Bn detector is similar to that of a standard pin detector, but there is special wide bandgap Al As0.08 Sb0.92 barrier layer in the n Bn detector, in which the depletion region of n Bn detector exists. The n Bn design has many advantages, such as low dark current and high quantum efficiency, because the n Bn design can suppress the generation–recombination(GR)current that is the main composition of standard pin detector dark current. The constant slope of the Arrhenius plot of J0–1/T indicates the absence of the generation–recombination dark current. We fabricate an n Bn detector with a quantum efficiency(QE) maximum of ~ 60% under-0.2-V bias voltage. The In As Sb n Bn detectors may be a competitive candidate for midwavelength infrared detector.展开更多
We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed an...We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states.There are two different mechanisms for the origin of the PL intensity quenching for the Al In As Sb digital alloy.The high-temperature activation energy E_(1)is positively correlated with the interface thickness,whereas the low-temperature activation energy E_(2)is negatively correlated with the interface thickness.A quantitative high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)study shows that the interface quality improves as the interface thickness increases.Our results confirm that E_(1)comes from carrier trapping at a state in the In Sb interface layer,while E_(2)originates from the exciton binding energy due to the roughness of the Al As interface layer.展开更多
By optimizing theⅤ/Ⅲbeam-equivalent pressure ratio,a high-quality InAs/GaSb type-Ⅱsuperlattice material for the long-wavelength infrared(LWIR)range is achieved by molecular beam epitaxy(MBE).High-resolution x-ray d...By optimizing theⅤ/Ⅲbeam-equivalent pressure ratio,a high-quality InAs/GaSb type-Ⅱsuperlattice material for the long-wavelength infrared(LWIR)range is achieved by molecular beam epitaxy(MBE).High-resolution x-ray diffraction(HRXRD),atomic force microscopy(AFM),and Fourier transform infrared(FTIR)spectrometer are used to characterize the material growth quality.The results show that the full width at half maximum(FWHM)of the superlattice zero-order diffraction peak,the mismatching of the superlattice zero-order diffraction peak between the substrate diffraction peaks,and the surface roughness get the best results when the beam-equivalent pressure(BEP)ratio reaches the optimal value,which are 28 arcsec,13 arcsec,and 1.63?,respectively.The intensity of the zero-order diffraction peak is strongest at the optimal value.The relative spectral response of the LWIR detector shows that it exhibits a 100%cut-off wavelength of 12.6μm at 77 K.High-quality epitaxial materials have laid a good foundation for preparing high-performance LWIR detector.展开更多
High performance short-wavelength infrared PBn photodetectors based on InAs/GaSb/AlSb superlattices on GaSb substrate have been demonstrated.At 300 K,the device exhibits a 50%cut-off wavelength of~2.1μm as predicted ...High performance short-wavelength infrared PBn photodetectors based on InAs/GaSb/AlSb superlattices on GaSb substrate have been demonstrated.At 300 K,the device exhibits a 50%cut-off wavelength of~2.1μm as predicted from the band structure calculation;the device responsivity peaks at 0.85 A/W,corresponding to a quantum efficiency(QE)of 56%for 2.0μm-thick absorption region.The dark current density of 1.03×10^(-3)A/cm^(2)is obtained under 50 mV applied bias.The device exhibits a saturated dark current shot noise limited specific detectivity(D*)of 3.29×1010cm·Hz^(1/2)/W(at a peak responsivity of 2.0μm)under-50 mV applied bias.展开更多
In this paper,we demonstrate bias-selectable dual-band short-or mid-wavelength infrared photodetectors based on In0.24Ga0.76As0.21Sb0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2....In this paper,we demonstrate bias-selectable dual-band short-or mid-wavelength infrared photodetectors based on In0.24Ga0.76As0.21Sb0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2.2μm and 3.6μm,respectively.At 200 K,the short-wave channel exhibits a peak quantum efficiency of 42%and a dark current density of5.93×10^-5）/cm^2at 500 mV,thereby providing a detectivity of 1.55×10^11cm·Hz^1/2/W.The mid-wave channel exhibits a peak quantum efficiency of 31%and a dark current density of 1.22×10^-3A/cm^2at-300 mV,thereby resulting in a detectivity of 2.71×10^10cm·Hz^1/2/W.Moreover,we discuss the band alignment and spectral cross-talk of the dual-band n-i-p-p-i-n structure.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2014CB643903,2013CB932904,2012CB932701 and 2011CB922201the National Special Funds for the Development of Major Research Equipment and Instruments of China under Grant No 2012YQ140005+7 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB01010200the China Postdoctoral Science Foundation-funded Project under Grant No 2014M561029the Program for New Century Excellent Talents in University under Grant No NCET-10-0066the National High-Technology Research and Development Program of China under Grant No 2013AA031502the Science and Technology Innovation Project of Harbin City under Grant No2011RFLXG006the National Natural Science Foundation of China under Grant Nos 61274013,U1037602,61306013,51202046,and 61290303the China Postdoctoral Science Foundation under Grant Nos 2012M510144 and 2013T60366the Fundamental Research Funds for the Central Universities under Grant Nos HIT.NSRIF.2013006 and HIT.BRETIII.201403
文摘We report a type-Ⅱ InAs/GaSb superlattice three-color infrared detector for mid-wave （MW）, long-wave （LW）, and very long-wave （VLW） detections. The detector structure consists of three contacts of NIPIN architecture for MW and LW detections, and hetero-junction NIP architecture for VLW detection. It is found that the spectral crosstalks can be significantly reduced by controlling the minority carriers transport via doping beryllium in the two active regions of NIPIN section. The crosstalk detection at MW, LW, and VLW signals are achieved by selecting the bias voltages on the device. At 77K, the cutoff wavelengths of the three-color detection are 5.3μm （at OmV）, 141μm （at 300mV） and 19μm （at -20mV） with the detectivities of 4.6xlO11 cm.Hzl/ZW-1, 2.3×10^10 cm.Hzl/2W-1, and 1.0×10^10cm.Hzl/2W-1 for MW, LW and VLW. The crosstalks of the MW channel, LW channel, and VLW channel are almost 0, 0.25, and 0.6, respectively.
基金supported by the National Basic Research Program of China(Grant Nos.2013CB932904 and 2011CB922201)the National Special Funds for the Development of Major Research Equipment and Instruments,China(Grant No.2012YQ140005)the National Natural Science Foundation of China(Grant Nos.61274013,61290303,and 61306013)
文摘A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 μm, at 77 K.A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of-20 mV, yielding a peak specific detectivity of 5.89×10^10cm·Hz^1/2·W^-1. The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK.
基金Project supported by the National Key Technology R&D Program of China(Grant No.2018YFA0209104)the Key R&D Program of Guangdong Province,China(Grant No.2018B030329001)the Major Program of the National Natural Science Foundation of China(Grant No.61790581)。
文摘The eight-band κ·p model is used to establish the energy band structure model of the type-II InAs/GaSb superlattice detectors with a cut-off wavelength of 10.5μm,and the best composition of M-structure in this type of device is calculated theoretically.In addition,we have also experimented on the devices designed with the best performance to investigate the effect of the active region p-type doping temperature on the quantum efficiency of the device.The results show that the modest active region doping temperature(Be:760℃)can improve the quantum efficiency of the device with the best performance,while excessive doping(Be:>760℃)is not conducive to improving the photo response.With the best designed structure and an appropriate doping concentration,a maximum quantum efficiency of 45% is achieved with a resistance-area product of 688?·cm^2,corresponding to a maximum detectivity of 7.35×10^11cm·Hz^1/2/W.
基金Project supported by the National Basic Research Program of China(Grant Nos.2014CB643903,2013CB932904,2012CB932701,and 2011CB922201)the National Special Funds for the Development of Major Research Equipment and Instruments,China(Grant No.2012YQ140005)+2 种基金the National Natural Science Foundation of China(Grant Nos.61274013,U1037602,61306013,and 61290303)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB01010200)China Postdoctoral Science Foundation(Grant No.2014M561029)
文摘In this paper we focused on the mask technology of inductively coupled plasma（ICP） etching for the mesa fabrication of infrared focal plane arrays（FPA）.By using the SiO_2 mask,the mesa has higher graphics transfer accuracy and creates less micro-ripples in sidewalls.Comparing the IV characterization of detectors by using two different masks,the detector using the SiO_2 hard mask has the R_0A of 9.7×10~6 Ω·cm^2,while the detector using the photoresist mask has the R_0A of3.2 × 10~2 Ω·cm^2 in 77 K.After that we focused on the method of removing the remaining SiO_2 after mesa etching.The dry ICP etching and chemical buffer oxide etcher（BOE） based on HF and NH4 F are used in this part.Detectors using BOE only have closer R_0A to that using the combining method,but it leads to gaps on mesas because of the corrosion on AlSb layer by BOE.We finally choose the combining method and fabricated the 640×512 FPA.The FPA with cutoff wavelength of 4.8 μm has the average R_0A of 6.13 × 10~9 Ω·cm^2 and the average detectivity of 4.51 × 10~9 cm·Hz^（1/2）.W^（-1）at 77 K.The FPA has good uniformity with the bad dots rate of 1.21%and the noise equivalent temperature difference（NEDT） of 22.9 mK operating at 77 K.
基金supported by the National Key Technology R&D Program of China(Grant Nos.2018YFA0209104 and 2016YFB0402403)
文摘A long-/long-wave dual-color detector with N-M-π-B-π-M-N structure was developed based on a type-Ⅱ InAs/GaSb superlattice. The saturated responsivity was achieved under low bias voltage for both channels. The device could be operated as a single detector for sequential detection and showed high quantum efficiencies. The peak quantum efficiencies of long-wavelength infrared band-1(blue channel) and long-wavelength infrared band-2(red channel) were 44% at 6.3 μm under 20 mV and 57% at 9.1 μm under-60 mV, respectively. The optical performance for each channel was achieved using a 2 μm thickness absorber. Due to the high QE, the specific detectivities of the blue and red channels reached5.0×10^(11) cm·Hz^(1/2)/W at 6.8 μm and 3.1×10^(11) cm·Hz1^(1/2)/W at 9.1 μm, respectively, at 77 K.
基金supported by the National Basic Research Program of China(Grant Nos.2018YFA0209102 and 2019YFA070104)the National Natural Science Foundation of China(Grant Nos.61790581 and 61274013)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22)。
文摘The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solution(citric acid,phosphoric acid,hydrogen peroxide,deionized water),the best solution ratio is obtained.After comparing different passivation materials such as sulfide+SiO_(2),Al_(2)O_(3),Si_(3)N_(4) and SU8,it is found that SU8 passivation can reduce the dark current of the device to a greater degree.Combining this wet etching and SU8 passivation,the of VLWIR detector with a mesa diameter of 500μm is about 3.6Ω·cm^(2) at 77 K.
基金National Key Technologies Research and Development Program of China(Grant No.2018YFA0209104)the Major Program of the National Natural Science Foundation of China(Grant No.61790581).
文摘we report n Bn photodetectors based on In As0.91 Sb0.09 with a 100% cut-off wavelength of 4.75 μm at 300 K. The band of an n Bn detector is similar to that of a standard pin detector, but there is special wide bandgap Al As0.08 Sb0.92 barrier layer in the n Bn detector, in which the depletion region of n Bn detector exists. The n Bn design has many advantages, such as low dark current and high quantum efficiency, because the n Bn design can suppress the generation–recombination(GR)current that is the main composition of standard pin detector dark current. The constant slope of the Arrhenius plot of J0–1/T indicates the absence of the generation–recombination dark current. We fabricate an n Bn detector with a quantum efficiency(QE) maximum of ~ 60% under-0.2-V bias voltage. The In As Sb n Bn detectors may be a competitive candidate for midwavelength infrared detector.
基金Project supported by the National Key Technologies Research and Development Program of China(Grant Nos.2019YFA0705203,2019YFA070104,2018YFA0209102,and 2018YFA0209104)the Major Program of the National Natural Science Foundation of China(Grant Nos.61790581,62004189,and 61274013)+2 种基金the Aeronautical Science Foundation of China(Grant No.20182436004)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22)the Research Foundation for Advanced Talents of the Chinese Academy of Sciences(Grant No.E27RBB03)。
文摘We compared the photoluminescence(PL)properties of Al In As Sb digital alloy samples with different periods grown on Ga Sb(001)substrates by molecular beam epitaxy.Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states.There are two different mechanisms for the origin of the PL intensity quenching for the Al In As Sb digital alloy.The high-temperature activation energy E_(1)is positively correlated with the interface thickness,whereas the low-temperature activation energy E_(2)is negatively correlated with the interface thickness.A quantitative high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)study shows that the interface quality improves as the interface thickness increases.Our results confirm that E_(1)comes from carrier trapping at a state in the In Sb interface layer,while E_(2)originates from the exciton binding energy due to the roughness of the Al As interface layer.
基金Project supported by the National Key Technology R&D Program of China(Grant Nos.2018YFA0209104,2018YFA0209102,2019YFA0705203,and2019YFA070104)the National Natural Science Foundation of China(Grant Nos.61790581,61274013,and 62004189)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22).
文摘By optimizing theⅤ/Ⅲbeam-equivalent pressure ratio,a high-quality InAs/GaSb type-Ⅱsuperlattice material for the long-wavelength infrared(LWIR)range is achieved by molecular beam epitaxy(MBE).High-resolution x-ray diffraction(HRXRD),atomic force microscopy(AFM),and Fourier transform infrared(FTIR)spectrometer are used to characterize the material growth quality.The results show that the full width at half maximum(FWHM)of the superlattice zero-order diffraction peak,the mismatching of the superlattice zero-order diffraction peak between the substrate diffraction peaks,and the surface roughness get the best results when the beam-equivalent pressure(BEP)ratio reaches the optimal value,which are 28 arcsec,13 arcsec,and 1.63?,respectively.The intensity of the zero-order diffraction peak is strongest at the optimal value.The relative spectral response of the LWIR detector shows that it exhibits a 100%cut-off wavelength of 12.6μm at 77 K.High-quality epitaxial materials have laid a good foundation for preparing high-performance LWIR detector.
基金the National Key Technologies R&D Program of China(Grant Nos.2019YFA0705203 and 2018YFA0209104)Major Program of the National Natural Science Foundation of China(Grant No.61790581)Aeronautical Science Foundation of China(Grant No.20182436004).
文摘High performance short-wavelength infrared PBn photodetectors based on InAs/GaSb/AlSb superlattices on GaSb substrate have been demonstrated.At 300 K,the device exhibits a 50%cut-off wavelength of~2.1μm as predicted from the band structure calculation;the device responsivity peaks at 0.85 A/W,corresponding to a quantum efficiency(QE)of 56%for 2.0μm-thick absorption region.The dark current density of 1.03×10^(-3)A/cm^(2)is obtained under 50 mV applied bias.The device exhibits a saturated dark current shot noise limited specific detectivity(D*)of 3.29×1010cm·Hz^(1/2)/W(at a peak responsivity of 2.0μm)under-50 mV applied bias.
基金Project supported by the National Basic Research Program of China(Grant Nos.2016YFB0402403 and 2013CB932904)the National Natural Science Foundation of China(Grant Nos.61290303 and 61306013)China Postdoctoral Science Foundation(Grant No.2016M601100)
文摘In this paper,we demonstrate bias-selectable dual-band short-or mid-wavelength infrared photodetectors based on In0.24Ga0.76As0.21Sb0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2.2μm and 3.6μm,respectively.At 200 K,the short-wave channel exhibits a peak quantum efficiency of 42%and a dark current density of5.93×10^-5）/cm^2at 500 mV,thereby providing a detectivity of 1.55×10^11cm·Hz^1/2/W.The mid-wave channel exhibits a peak quantum efficiency of 31%and a dark current density of 1.22×10^-3A/cm^2at-300 mV,thereby resulting in a detectivity of 2.71×10^10cm·Hz^1/2/W.Moreover,we discuss the band alignment and spectral cross-talk of the dual-band n-i-p-p-i-n structure.
