Photoelectronic Properties of End-bonded InAsSb Nanowire Array Detector under Weak Light

Abstract

A simple fabrication of end-bonded contacts InAsSb NW (nanowire) array detector to weak light is demonstrated in this study. The detector is fabricated using InAsSb NW array grown by molecular beam epitaxy on GaAs substrate. The metal-induced gap states are induced by the end-bonded contact which suppresses the dark current at various temperatures. The existence of the interface dipole due to the interfacial gap states enhances the light excitation around the local field and thus upgrades the photoresponsivity and photodetectivity to the weak light. The light intensity of the infrared light source in this report is 14 nW/cm2 which is about 3 to 4 orders of magnitude less than the laser source. The responsivity of the detector has reached 28.57 A/W at room temperature with the light (945 nm) radiation, while the detectivity is 4.81 × 1011 cm·Hz1/2 W−1. Anomalous temperature-dependent performance emerges at the variable temperature experiments, and we discussed the detailed mechanism behind the nonlinear relationship between the photoresponse of the device and temperatures. Besides, the optoelectronic characteristics of the detector clarified that the light-trapping effect and photogating effect of the NWs can enhance the photoresponse to the weak light across ultraviolet to near-infrared. These results highlight the feasibility of the InAsSb NW array detector to the infrared weak light without a cooling system.

Enhanced photoresponse of the CdS microwire photodetectors based on indium ion implantation

“…The rise time and decay time are estimated to be ∼354 ms and ∼3.82 s, respectively. The long decay time can be attributed to the trapping of photoexcited carriers by trap states induced by intrinsic defects in the CdS microwires [34,35].…”

Review on III–V Semiconductor Nanowire Array Infrared Photodetectors

“…demonstrated an InAsSb nanowire array detector grown by molecular beam epitaxy on a GaAs substrate. [ 63 ] It was shown that by depositing a very thin layer of Au (8 nm) on top of nanowires, the existence of the interface dipole can enhance the photoresponsivity and photodetectivity to the weak light with a responsivity of 28.57 A W −1 and detectivity of 4.81×10 11 cm Hz −1/2 W −1 being obtained at room temperature under weak light illumination of 14 nW cm −2 at a wavelength of 945 nm. [ 63 ]…”

“…Due to the reduced active material and engineerable light absorption properties, nanowire array infrared photoconductors with good performance and (near) room temperature operation have been demonstrated. [6,63] Owing to the strong and tunable resonance modes that are sup-ported in a nanowire array, [6,61] proper selection of wire diameter can lead to the increase of the absorptance by more than 10 times of magnitude at a specific wavelength, in comparison with a thin planar film with the same amount of material. [61] By varying the nanowire diameters, Li et al demonstrated wavelengthselective multipixel GaAsSb nanowire array photodetectors with multiple light detection channels that cover both visible and NIR ranges, when no optical filters were used, as shown in Figure 4.…”

“…[6] Svensson et al demonstrated InAs 1-x Sb x nanowire array based MWIR photoconductors with a diameter-dependent photoresponse and a cutoff wavelength up to 5.7 μm (where 20% of the maximum photocurrent is obtained) at a temperature of 5 K. [61] Furthermore, Yao et al demonstrated an InAsSb nanowire array detector grown by molecular beam epitaxy on a GaAs substrate. [63] It was shown that by depositing a very thin layer of Au (8 nm) on top of nanowires, the existence of the interface dipole can enhance the photoresponsivity and photodetectivity to the weak light with a responsivity of 28.57 A W −1 and detectivity of 4.81×10 11 cm Hz −1/2 W −1 being obtained at room temperature under weak light illumination of 14 nW cm −2 at a wavelength of 945 nm. [63]…”

“…[56,57] The high radiation tolerance demonstrated in III-V nanowires [56][57][58] could make them also desirable for space applications where higher cost is even more affordable than in terrestrial applications. In particular, for infrared photodetection to cover near-infrared (NIR), shortwave infrared (SWIR) and mid-wave infrared (MWIR) ranges, narrow bandgap semiconductor material-based nanowires such as GaAsSb, [6][7][8][9] InGaAs, [36,59] InAs [27,60] and InAsSb [26,[61][62][63] are highly attractive, as they may provide possible solutions to overcome the problems that planar infrared photodetectors encounter, such as low responsivity and detectivity, high dark current and low working temperature, through reduced device size/volume and increased flexibility in device design both optically and electrically.…”