Internal Photoemission in a-Si:H Schottky-Barrier and MOS Structures

Abstract

Internal photoemission of metal/a-Si: H and metal/SiO 2 /a-Si:H systems have been measured in the temperature range 86 to 300 K. The height of the potential barriers at the Pd/a-Si:H and SiO 2 /a-Si:H interfaces have been determined to be 0.98 and 3.03 eV, respectively. The temperature coefficients of the Schottky barrier height and the optical band gap of a-Si:H have been obtained to be 3.3×10 -4 and 2.7×10 -4 eV/K, respectively. Appreciable quantum yield below the photoemission threshold for an MOS structure is found to be dependent on preparation conditions of a-Si:H , being attributed to electron emission from the filled gap-states in the film.