Silicon–Hydrogen Bonding Configuration Modified by Layer Stacking Sequence in Silicon Heterojunction Solar Cells
Jeong-Ho An, Joon‐Ho Oh, Kyung Taek Jeong, Oh‐Min Kwon, Soong Ju Oh, Kyoung‐Ho Kim, Kyoung‐Ho Kim, Sunwook Kim, Min Jong Keum, Hee‐eun Song, Ka‐Hyun Kim, Ka‐Hyun Kim
Abstract
Recent improvements in highly efficient crystalline silicon (c-Si) solar cells have relied on surface passivation. Hydrogen plays a crucial role in the surface passivation of silicon heterojunction (SHJ) solar cells because Si–H bonds passivate dangling bonds in amorphous silicon and on the c-Si surface. In this work, we demonstrate that the Si–H bonding configuration is modified by layer stacking sequence for SHJs. The quality of surface passivation strongly correlates with low-temperature hydrogen effusion from the SHJ structure. Our results show that the deposition of doped layers on intrinsic amorphous silicon supplies additional hydrogen to the amorphous/crystalline heterostructure. Moreover, the deposition of a p-layer modifies the microstructure of the intrinsic layer underneath, whereas depositing an n-layer does not induce structural changes. We suggest that the low-temperature hydrogen effusion characteristics can be used as a sensitive indicator for examining the passivation quality of SHJ solar cells.