Characterization of ZnCdSe/ZnSSeTe MQWs Photodetectors Grown by MBE

ZnCdSe/ZnSSeTe MQWs photodetectors (PDs) were grown on p-GaAs substrate by molecular beam epitaxy. From temperature-dependent PL spectra, a thermal activation energy corresponding to the Ten cluster-bound exciton was calculated to be 105meV. At 17 K, it was found that three absorptions points corresponding to the quantum well absorption were 2.71 eV, 2.685 eV, and 2.671 eV. It was also found that three near band-edge absorptions were 2.847 eV, 2.827 eV, and 2.816 eV corresponding to the ZnSSeTe epitaxial layers. The fabricated ZnCdSe/ZnSSeTe MQW pin photodetectors have shown that the responsivity has a sharp cut off at 870 nm corresponding to the band edge of GaAs substrate and that the peak responsivity was found to be 0.456 A/W at 810 nm. Such a high photo response and wide absorption spectrum might have more applications in commercial visible/UV photodetectors.