Room Temperature Infrared Electroluminescence from Thin-Film Polycrystalline Chalcopyrite Cu(In,Ga)Se2-Based Diodes

Abstract

AbstractEvidence of room-temperature infrared electroluminescence from thin-film polycrystalline CuInxGa1-xSe2-based diodes (0<×<0.4) has been observed by Fourier transform spectroscopy using a FT-Raman spectrophotometer that operates in the near-infrared spectral region. Electroluminescence spectra from ternary CuInSe2 and quaternary Cu(In,Ga)Se2 device structures are reported. In all electroluminescence cases we observe an approximate linear relationship of intensity to forward junction current. Film fabrication process determines to a great extent the optoelectronic properties of the emitters, and consequently, the characteristics of their luminescence spectra. Using a Gaussian multi-peak curve-fit routine to analyze electroluminescence spectra, we can deduce the position, width and relative intensity of the dominant optical transitions. Our purpose in this contribution is two-fold: (1) To report the room-temperature electroluminescence phenomena from chalcopyrite Cu(In,Ga)Se2 polycrystalline thin-films, and (2) to demonstrate electroluminescence as a viable technique to optically characterize Cu(In,Ga)Se2 materials using diode structures at RT.