Analysis of luminescence method applicability for determination of Cd1-xZnxTe composition

Abstract

Physical fundamentals are analyzed for the method of determination of Cd 1-x Zn x Te composition x from measurements of the luminescence band peak position, emission being caused by annihilation of bound exciton shallow neutral acceptor complexes at 4.2 K. Found are the conditions when application of the method discussed enables to obtain reliable x values.

Analysis of luminescence method for determination of Cd1-xZnxTe composition

“…2a and [6]) 1 , and m hν = (1.590 + 0.445х + 0.339х 2 ) eV (2) as was found when studying the excitonic luminescence spectra of Cd 1-x Zn x Te crystals (see Fig. 2b and [8]) 2 .…”

“…Further we consider that the pointed A 0 X, D 0 X and X induced emission bands could be the only ones observed in the 4.2 K excitonic luminescence spectrum of Cd 1-x Zn x Te. This is valid for Cd 1-x Zn x Te compounds (0< x <1), see, for example, Fig.1 and [2,8,11]. Therefore, to find the x value by using the discussed luminescence method one must separate the A 0 X induced emission band in Cd 1-x Zn x Te emission spectra.…”

“…(2) shows the result of averaging (for details see [8]) somewhat different hν m vs x calibration dependencies for Cd 1-x Zn x Te crystals given in [9,10]. In [10] hν m vs x dependency is given for T = 1.6 K; similar to [8] we suppose that this dependency is also valid at T = = 4.2 K, as it is known that the peak position of the emission band induced by bound exciton annihilation practically does not depend on temperature at T ≤ 4.2 K. In particular, it is valid for Cd 1-x Zn x Te with x = 0 (CdTe) and x = 1 (ZnTe) [7]. Obviously, as one uses the averaged calibration curves a definite inaccuracy in the x determination appears (it is shown in Fig.…”

“…2b). Given in [8] Eq. (A8) needed to construct the calibration curve (2) is the best fit for presented in [9] the experimental hν m (A 0 X) vs. x dependence made by us.…”

“…Earlier [8] a preliminary examination of this method was made. In the present work which is a continuation of [8], some further comment on the discussed luminescence method will be made (for convenience some data given in [8] are repeated in it). Its essence lies in the following.…”