ABSTRACT

The optical absorption spectra of Figure 22 were fitted with the BM model self-consistently. Since the total residual strain is known exactly from the position of the O'* order satellite peaks in the HRXRD spectra, the In^A si^P and Ga>Ini_yP alloy compositions, x and y, are coupled. We used the best estimates of x and y given by HRXRD to fit the 7 InAs^Pi-^/Ga^Ini-yP MQW samples of Figure 22 using 9 meV and 6 meV for the heavy-hole and light-hole excitonic binding energies. We then varied x and y until all samples could be fitted exactly. These values were then confirmed by using

them to improve the fits to the HRXRD patterns. The BM fits to the optical absorption peaks are identified with short arrows in Figure 22 using the same notation, E„h , E„l , etc. as for the InAsxPi_x/InP samples. The results of the fits are reported in Table 1. Oddly enough, it appears that the positions of the predicted E m peaks are in better agreement for the strain-balanced samples than for the InAsP/InP MQW samples although the predicted transitions are, again, at a slightly higher energy than the experimental transitions.