Donor–acceptor pair photoluminescence spectra analysis in CdTe:Ag

Abstract

Articles you may be interested inEffect of donor-acceptor concentration ratios on nonradiative energy transfer in closely packed CdTe quantum dots Appl. Phys. Lett. 95, 133123 (2009); Photoluminescence ͑PL͒ spectra of CdTe single crystals and films, undoped and Ag-doped, were studied in the range of the photon energy (h): 1.5-1.6 eV, at 10 K. Films were doped during the growth process. Thin layers of Ag were vacuum evaporated onto the surface of undoped CdTe crystals, then were submitted to thermal annealing in a N 2 ϩ2% H 2 ambient at 400°C for 3 h. PL spectra of crystals exhibit a donor-acceptor pair ͑DAP͒ emission at hϭ1.491 eV ͑named here DAP Ag 2 ) with the highest intensity with respect to other signals. The PL of films is characterized by a peak at 1.5 eV followed by several phonon replicas. In both cases, the DAP emissions are due to the Ag-impurity presence and are accompanied by phonon replicas. Unannealed intrinsic crystals exhibit a unique broad DAP Ag 1 peak at hϭ1.501 eV, and one month aged at room temperature Ag-doped crystals only display a wide DAP Ag 2 peak at hϭ1.491 eV with 65% of its initial intensity, that reflects a reduced density of Ag diffused-doping levels. The origin of DAP lines in a PL spectra of CdTe:Ag has not been completely well defined until now, and we have introduced some explanatory conclusions about and a simple model for electronic transitions. This issue is important because Ag is an everpresent residual impurity in CdTe.

Donor-acceptor pair luminescence of nitrogen-implanted ZnO single crystal

“…In addition, the verification of p-type conduction by Hall effect measurement is difficult in highly compensated material. 16 As in other II-VI and III-V semiconductors, 17,18 the donor-acceptor-pair ͑DAP͒ transition in ZnO is an important light-emission mechanism. The observations of DAP luminescence in ZnO and other acceptor-related luminescence, such as acceptor bound excitons 8 and free electron + acceptor recombination, 19 have been reported.…”

Effects of composition and thermal treatment on VOC‐limiting defects in single‐crystalline Cu2ZnSnSe4 solar cells

“…Finally, DAP lineshapes in semiconductor literature are commonly modeled with a Gaussian shape, and we thus use them in fitting to this model. The gradual transition of Peak 1 from BI (Gaussian) to DAP transitions between CP2 and CP2‐A further justifies the use of the Gaussian lineshape for the latter case in this current study 38,43 …”

Effect of Colloidal Silver on Optical Transmittance Characteristics of Bulk Cadmium Zinc Telluride Crystals

“…In the existing literature, silver has been incorporated by the following techniques: (i) vacuum evaporation, [1][2][3] (ii) implantation of silver ions, 4-6 (iii) nuclear transmutation, 7,8 (iv) diffusion in a quartz tube, 9,10 (v) two-step diffusion, 11 and (vi) dipping in silver nitrate solution. 12 Silver, thus introduced into the lattice, occupies a substitution site and contributes to the p-type carrier concentration.…”

“…Substituted Ag has been found to exhibit decay or aging in its properties on room-temperature storage. 2,[9][10][11] Properties of Ag-doped CdTe and CZT have been studied using various techniques such as photoluminescence (PL), 1,2,4,5,[9][10][11]13,14 capacitance-voltage (CV) measurements, 3,7,9,10 and perturbed angular correlation (PAC). 12,15,16 In this paper, we report the results of a systematic study conducted on the transmittance characteristics of p-type CZT wafers upon application of silver paste at room temperature.…”