Development of High Efficiency Thin-Substrate Silicon Solar Cells with Controlled Nano-Interface

硅异质结太阳能电池具有实现高转换效率的潜力。为了获得高开路电压，c-Si表面悬垂键的钝化是必不可少的。氢化非晶硅（a-Si:H）是异质结太阳能电池中最常用的钝化材料之一。已知a- si:H具有较高的钝化质量，但在较高的沉积温度下沉积时，会出现有害的外延生长，使钝化效果恶化。在本研究中，采用宽带隙非晶氧化硅（a- sio:H）或纳米晶3C-SiC作为常规a- si:H的替代品来抑制外延生长，从而导致极低的表面复合速度。到目前为止，在708 mV的高开路电压下，效率达到了20.1%，达到了最初的目标。

Silicon heterojunction solar cells have the potential to achieve high conversion efficiencies. In order to achieve high open circuit voltages, passivation of dangling bonds on the c-Si surface is indispensable. One of the most used passivation materials for heterojunction solar cells is the hydrogenated amorphous silicon (a-Si:H). a-Si:H is known to have a high passivation quality, but it shows harmful epitaxial growth when deposited at relatively high deposition temperatures, deteriorating the passivation effect. In this study wide-bandgap amorphous silicon oxide (a-SiO:H) or nano-crystalline 3C-SiC is applied as an alternative to the conventional a-Si:H to suppress the epitaxial growth, resulting with a very low surface recombination velocity. Up to now, an efficiency of 20.1 % has been achieved with a high open circuit voltage of 708 mV, and the original goals have been met.