3:00 PM - 3:15 PM
△ [10p-N104-8] Evaluation of damage to c-Si substrate induced by plasma enhanced chemical vapor deposition of a-Si:H films
Keywords:Silicon heterojunction solar cells, plasma enhanced chemical vapor deposition
Silicon heterojunction solar cells is attracting attention as a highly efficient solar cell. Up to now, there has been a lot of research on the increase of carrier lifetime by the deposition of amorphous layers, but the existence of damage during the deposition of amorphous layers on c-Si has not been clarified. In this study, we accurately reduce a-Si thickness by using a wet etching method and evaluated the damage layer on the c-Si induced by a-Si deposition.In the experiment, a-Si was deposited by plasma enhanced chemical vapor deposition on the n-type c-Si (100) after removing the native oxide with a diluted HF. In order to evaluate damage to the c-Si, H2O2 was used to form an oxide film on the a-Si surface, surface passivation was performed with a quinhydrone-methanol after removing oxide film with a diluted HF, then the carrier lifetime was measured by the QSSPC method. By repeating this process, the damage layer on the c-Si was removed gradually.In this study, a damage layer on the c-Si surface at about 2.60 nm was confirmed and it does not disappear at the process temperature of SHJ solar cells (200°C, 30 minutes).