선택적 캐리어 수집을 위한 터널 산화막을 이용한 결정질 실리콘 태양전지

Abstract

In silicon solar cells, the doping process is performed to form a Back Surface Field (BSF) layer and is followed by manyother processes. In this study, phosphorus doped a-Si:H doped at a high concentration in the tunnel oxide layer was crystallizedthrough furnace annealing and Excimer Laser Annealing (ELA), in order to apply it to the Polycrystalline (Poly) - BSF layer in theTunnel Oxide Passivated Contact (TOPCon) structure. In the excimer laser annealing fabrication process, an XeCl excimer laser witha wavelength of 308 nm was used, and the thickness of the a-Si layer and energy density of the laser were varied from 20 to 40 nm andfrom 390 to 450 mJ/cm2, respectively. The highest carrier lifetime and implied VOC were found to be 588 ㎲ and 697 mV, respectively,at an a-Si thickness of 20 nm and energy density of the laser of 450 mJ/cm2. The TOPCon cell was fabricated using wet oxidation andplasma oxidation. Its efficiency and FF were found to be higher when fabricated using the wet process, with values of 19.41% and74.8%, respectively, while its VOC and JSC values were higher when it was fabricated using plasma oxidation, with values of 41.04mJ/cm2and 644 mV, respectively. Therefore, if the conditions providing for a high implied VOC and carrier lifetime and sufficientcrystallization were found, the efficiency of n-type TOPCon solar cells could be increased.