The inherently disordered nature of hydrogenated amorphous silicon ($a$-Si:H) obscures the influence of atomic features on the trapping of holes. To address this, we have created a set of over two thousand ab initio structures of $a$-Si:H and explored the influence of geometric factors on the occurrence of deep hole traps using density-functional theory. Statistical analysis of the relative contribution of various structures to the trap distribution shows that floating bonds and ionization-induced displacements correlate most strongly with hole traps in our ensemble.

• Received 2 August 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.146805