Study of the optical transitions in electrodeposited CuInSe2 thin films

Abstract

Optical absorption coefficients of electrodeposited CuInSe, thin films were determined from the measured transmittance and reflectance at normal incidence of light in the wavelength range 400 to 2000 nm. As-deposited CuInSe, is found to be a direct-gap semiconductor with an allowed direct transition whose gap energy is Ega = 0.96 eV and a forbidden direct transition whose gap energy is Egf = 1.38 eV. After heat treatment of the films at 400 "C, a decrease in the optical absorption was observed at energies below 1.1 eV. Heat-treated films showed an allowed direct transition with EL, = 1.00 eV, close to the value for as-deposited samples, but in this last case the forbidden direct transition was not observed.

CuInSe2 nanotube arrays for efficient solar energy conversion

“…3. The band gap of the nanotube arrays was determined to be 1.04 eV which corroborates very well with the observed CISe band gap energies at room temperature as reported in literature 54,59,60 .…”

Electrochemically Induced Atom-by-Atom Growth of ZnS Thin Films: A New Approach for ZnS Co-deposition

“…It has been reported that ZnS is a direct band gap semiconductor and therefore plots of ( Ah ν) 2 versus h ν should be straight lines with intercepts on the energy axis giving the band gaps of the films . Such a plot for ZnS thin films electrodeposited at various times is shown in Figure .…”

Synthesis and characterization of Sb2Te3 nanofilms via electrochemical co-deposition method

“…3, the band gap decreased with an increase of the deposition time. It has been reported that Sb 2 Te 3 is a compound-semiconductor with a indirect band gap and therefore, the plots of (ahm) 2 versus hm should be a straight line and intercepts on energy axis would give the band gap of the film [29]. The band gaps of electrodeposited Sb 2 Te 3 thin films for 35 and 10 min were found to be 0.29 and 0.46 eV, respectively.…”