Pressure dependence of photoluminescence of ZnTe/Zn1-xCdxTe strained-layersuperlattice

Photoluminescence (PL) spectra of ZnTe/Zn1-xCdxTe (x = 0.23) strained-layer superlattice (SLS) samples were studied at hydrostatic pressures up to 4.8 GPa at room temperature. A sublinear pressure dependence of the PL peaks f or both the heavy-hole exciton and the donor-acceptor pair was observed. Th e first- and second-order pressure coefficients of the PL peaks were obtain ed by a least-squares fit. An analytical expression for the heavy-hole exci ton was also derived. The pressure coefficients obtained from the analytica l expression are 104 meV GPa(-1) and -4.44 meV GPa(-1), in excellent agreem ent with the experimental values of 103.9 meV GPa(-1) and -4.5 meV GPa(-2). It is shown that the contribution to the linear pressure coefficient comes exclusively from the hydrostatic component. Both hydrostatic and biaxial t erms are responsible for the second-order pressure coefficient, with a nega tive contribution of -6.07 meV GPa(-2) and a positive contribution of 1.63 meV GPa(-2), respectively. Copyright (C) 2001 John Wiley & Sons, Ltd.