Electroluminescence at silicon band gap energy from mechanically pressed indium–tin–oxide/Si contact

Abstract

Room temperature electroluminescence (EL) corresponding to Si band gap energy is observed from mechanically pressed indium–tin–oxide (ITO)/Si contact. The intensity of luminescence is pressure dependent and highly related to the current–voltage characteristics. Increasing pressure simultaneously reduces the rectification property and the luminescence. The physical reason for EL is attributed to the formation of an air gap between the ITO and the Si substrate. The role of the air gap is similar to the oxide layer in the metal–oxide–semiconductor structure. The influence of surface quality of the Si substrate on the luminescence spectrum is also studied, and found to be significant.