Effect of surface preparation on the 77 K photoluminescence of CdTe

Abstract

Photoluminescence spectra were obtained at 77 K for three undoped CdTe single crystal specimens whose surfaces were prepared by mechanical, conventional chemimechanical, and modified hydroplane polishing techniques, respectively. The hydroplane polished sample was found to be a much brighter source of photoluminescence than either of the other two specimens. In addition, hydroplane polishing produced a photoluminescence spectrum in which nearly all of the emission occurred in a band centered at 1.58 eV rather than in the well-known defect band at 1.42 eV. We interpret these results as providing evidence that hydroplane polishing of CdTe produces a surface having a low density of defects.

Low temperature photoluminescence spectroscopy of thin film, polycrystalline CdTe/CdS solar cell structures

“…It is usually ascribed to intrinsic defects/impurities and, consequently, is known as the 'defect band'. Although most research has concentrated on investigating bulk defects, Myers et al [18] showed that surface states could very well be responsible for the shape of the defect band. A number of explanations exist regarding the recombination mechanism involved including band-acceptor (e-A) transitions [17], donor-acceptor-pair (DAP) recombination [9,19,20] and internal transitions within highly localized defects [21][22][23].…”

Effect ofIn SituThermal Annealing on Structural, Optical, and Electrical Properties of CdS/CdTe Thin Film Solar Cells Fabricated by Pulsed Laser Deposition

“…Higher oc was observed on all iTAP processed solar cells as compared to the reference device without iTAP. The increased oc may be attributed to the improved CdS/CdTe interface through interdiffusion at the interface [25] facilitated by the iTAP, which is supported by the monotonic increase of the oc with increasing iTAP duration below 20 min. The best oc ∼724 mV was obtained at 15 min.…”

Photoluminescence studies of CdTe polycrystalline films

“…For the first time, the relatively broad spectral band peaking at 1.476 eV was observed by Dean et al [11]. A number of recombination mechanisms with participation of bulk and surface defects have been proposed to explain this emission [12][13][14][15][16][17][18][19].…”