Electrical and optical characterization of n-InAsSb/n-GaSb heterojunctions

Abstract

Articles you may be interested inDual-wavelength sensitive AlGaN/GaN metal-insulator-semiconductor-insulator-metal ultraviolet sensor with balanced ultraviolet/visible rejection ratiosWe report the electrical properties of n-InAsSb/n-GaSb heterojunctions as a function of the GaSb doping concentration. Because of the staggered type II band alignment, strong electron accumulation occurs on the InAsSb side. For low GaSb doping, depletion occurs on the GaSb side resulting in a Schottky-like junction as previously reported. As the GaSb doping increases, the built-in voltage as well as depletion width decreases as shown using self-consistent simulations. For GaSb doping levels above 5 ϫ 10 17 cm −3 , the junction loses its rectifying properties due to tunneling. Under zero and reverse bias voltage, the photoresponse of these diodes is solely due to the photovoltaic effect in the GaSb depletion region. For forward bias voltages Ͼ400 mV, we also observed a photoconductive response from the InAsSb layer. The proposed physical mechanism is quite different from the one suggested in a recent paper.

Monolithically Integrated InAsSb-Based nBnBn Heterostructure on GaAs for Infrared Detection

“…The cut-off wavelength of the photo-response for D2 is 2.1 µm, consistent with photon absorption in the GaSb buffer layer. No photo-response from the InAsSb layer (expected in the 2 to 4 µm wavelength range) could be detected when a negative bias is applied to D2, and this is in good agreement with what reported by Lackner et al [19]. The simulated band diagram in Fig.…”

“…The principle of operation of D2 is therefore analogous to that of a metal semiconductor Schottky photodetector. On the other hand, both Sharabani et al [18] and Lackner et al [19] reported dual-color IR (SWIR and MWIR) detection capability for similar heterostructures to D2 (InAsSb/GaSb detectors) when a positive bias was applied. However, D2 shows no extension of cut-off wavelength for positive voltages up to 0.2 V, beyond which it was not possible to collect spectra due to the high level of dark current.…”

“…To date, there has been no study of the performance of InAsSb nBn photodetectors with the bottom metal contact made on the n-type doped GaAs layer. On the other hand, previous studies showed that a n-type InAsSb/GaSb heterojunction demonstrated dual-color capability for detection of light at both short and medium infrared wavelengths (SWIR and MWIR) [18][19][20]. However, since photoconduction in the InAsSb/GaSb heterojunction detectors is associated with majority carriers, high dark current (mA order) and hence large > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 2 shot noise is expected especially when the detectors are biased for operation at room temperature.…”

InAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energy band simulations

“…The doping concentration of the substrate was 1 Â 10 18 cm À3 , which forms a tunnel junction with low n-doped InAsSb, as shown in an earlier work. 21 HR-XRD was employed to verify the layer composition, thickness, and strain state.…”

InAsSb and InPSb materials for mid infrared photodetectors

“…In a recent work we showed that the nInAsSb/n-GaSb heterojunction is rectifying for n-GaSb < 5×10 17 cm -3 and increasingly Ohmic above that concentration. [12] This is presumably due to the formation a tunneling junction for higher doping levels. Thus, if a back side contact device is to be used, the doping level in the GaSb side must be at least 10 18 cm -3 .…”