Density of states in hydrogenated microcrystalline silicon determined by space charge limited currents

Abstract We investigated space charge limited currents in μc-Si:H obtained by the conventional radio-frequency plasma-enhanced chemical-vapor-deposition (PECVD) method from silane diluted with hydrogen. This study was performed on Al/n+a-Si:H/μc-Si:H/n+a-Si:H/Cr (or SnO2) structures and some problems encountered during measurements are discussed. The values of the density of states at Fermi level N(EF) are in the range of 6×10 14 –2×10 16 cm −3 eV −1 and are strongly dependent on the crytalline fraction and the microstructure of the films.