Background limited performance in aluminum-free p-doped quantum well intersubband photodetectors

Background limited infrared photodetection has been achieved up to 100 K at normal incidence with two different Aluminum-free p-type quantum well intersubband photodetectors: one GaAs / Ga₀.₇₁In_0.29As_0.39P_0.61 and the other Ga_0.25In_0.75As_0.13P_00.87/G_0.o4Il_{0. 51}P. The samples were grown by low-pressure metalorganic chemical vapor deposition. Both detectors showed extended photoresponse cutoff wavelength over that of similar p-type GaAs/ G_0.49vI_0.51iP quantum well intersubband pholodetcctors by virtue of reduced valence band barrier heights. In this paper, the relative merits of both approaches are investigated in order to help determine the most appropriate technique for extending the range of photodetection to 8-12μpm.