Two kinds of short-period type II superlattices(SLs)InAs(6 monolayers(MLs))/GaSb(3 MLs)and InAs(8 MLs)/GaSb(8 MLs)which can serve for mid-infrared(MIR)detection have been grown by molecular beam epitaxy(MBE)on p-type GaSb(100)substrates.The cutoff wavelength for the two superlattices(SLs)was found to be around 4.8 lm at 300 K.The high resolution X-ray diffraction(HRXRD)measurements indicated that the InAs(8 MLs)/GaSb(8 MLs)SLs have better crystalline quality than that of the InAs(6 MLs)/GaSb(3 MLs)SLs.However,compared with infrared absorption in the 2.5–4.3 lm range,the optical absorption of InAs(6 MLs)/GaSb(3MLs)SLs was more excellent.This can be attributed to increase probability of the electron and hole wave function overlap in the thinner period thickness.
