Abstract
The absorption coefficients, alpha , of polycrystalline CuInS//2 and CuInSe//2 thin films have been determined at room temperature using transmission measurements. For each of these semiconductors, an absorption edge corresponding to the direct band-gapl transition (1. 54 plus or minus 0. 02 eV for CuInS//2 and 1. 00 plus or minus 0. 02 eV for CuInSe//2) is observed in the alpha vs h nu spectrum. In p-type CuInS//2 thin films, another edge is evident at lower energies (1. 41 multiplied by 1. 42 eV) and is attributed to transitions from a copper vacancy band to the conduction band. The effects of annealing on the absorption coefficient spectra of these chalcopyrite materials are presented. An additional absorption region, appears in the CuInSe//2 spectra at higher energies (h nu similar 1. 28 eV), and is critically dependent on the Se concentration of the films. This effect is discussed in terms of band structure, film stoichiometry and structural characteristics of the films.
Original language | American English |
---|---|
Pages (from-to) | 265-268 |
Number of pages | 4 |
Journal | Journal of vacuum science & technology |
Volume | 15 |
Issue number | 2 |
DOIs | |
State | Published - 1978 |
Externally published | Yes |
NREL Publication Number
- ACNR/JA-213-3540