Improving cell efficiency and increasing throughput in solar cell industry efforts were put on uniform texturization and optimum diffusion process. To reduce reflectivity, NaOH/KOH （sodium hydroxide/potassium hydrox...Improving cell efficiency and increasing throughput in solar cell industry efforts were put on uniform texturization and optimum diffusion process. To reduce reflectivity, NaOH/KOH （sodium hydroxide/potassium hydroxide） and IPA （isopropyl alcohol） are widely used in standard alkaline texturization of mono c-Si （crystalline silicon） （〈100〉 crystal orientation） wafers, where IPA promotes formation of uniform pyramidal structure but leads to unstable process. In this work, carbohydrates have been investigated as an additive in etchant solution. Moreover uniform phosphorus diffusion process for B2B （back to back） diffusion （loading two wafers in one single slot of quartz boat） has been investigated with single and multiple temperature plateaus. Impact of pre-oxygen step on phosphorus diffusion is investigated in which number of inactive phosphorus at the PSG （phosphosilicate glass）-Si interface is reduced. A batch of 156 PSQ （pseudo square） mono c-Si solar cells with 18%-18.20% efficiency was fabricated which is -0.3% higher than the standard process. The EL （electroluminescence image）, reff （carrier effective life time）, Voc （open circuit voltage）, Isc （short circuit current）, Pvk （peak power） and r/ （efficiency） have been examined and compared with standard.展开更多
文摘Improving cell efficiency and increasing throughput in solar cell industry efforts were put on uniform texturization and optimum diffusion process. To reduce reflectivity, NaOH/KOH （sodium hydroxide/potassium hydroxide） and IPA （isopropyl alcohol） are widely used in standard alkaline texturization of mono c-Si （crystalline silicon） （〈100〉 crystal orientation） wafers, where IPA promotes formation of uniform pyramidal structure but leads to unstable process. In this work, carbohydrates have been investigated as an additive in etchant solution. Moreover uniform phosphorus diffusion process for B2B （back to back） diffusion （loading two wafers in one single slot of quartz boat） has been investigated with single and multiple temperature plateaus. Impact of pre-oxygen step on phosphorus diffusion is investigated in which number of inactive phosphorus at the PSG （phosphosilicate glass）-Si interface is reduced. A batch of 156 PSQ （pseudo square） mono c-Si solar cells with 18%-18.20% efficiency was fabricated which is -0.3% higher than the standard process. The EL （electroluminescence image）, reff （carrier effective life time）, Voc （open circuit voltage）, Isc （short circuit current）, Pvk （peak power） and r/ （efficiency） have been examined and compared with standard.
