Room-Temperature Blackbody-Sensitive and Fast Infrared Photodetectors Based on 2D Tellurium/Graphene Van der Waals Heterojunction

Abstract

Emerging low-dimensional materials exhibit the potential in realizing next-generation room-temperature blackbody-sensitive infrared detectors. As a narrow band gap semiconductor, low-dimensional tellurium (Te) has been a focus of infrared detector research attention because of its high hole mobility, large absorptivity, and environmental stability. However, it is still a challenge to fabricate blackbody-sensitive Te-based infrared detectors with a low dark current and fast speed. In this work, a heterojunction device based on Te and graphene is constructed, achieving high detectivity and a fast response time from visible to mid-infrared. Specifically, under 2 μm laser irradiation, the heterojunction photodetector exhibits a detectivity of 1.04 × 10 9 cm Hz 1/2 W −1 , a fast response time of 28 μs, and good ambient stability. Moreover, the photodetector demonstrates a room-temperature blackbody sensitivity with the peak detectivity of up to 3.69 × 10 8 cm Hz 1/2 W −1 under zero bias. Linear array devices are further explored and show good performance uniformity for potential imaging applications. Our work demonstrates that the Te/graphene heterojunction detector will be one of the competitive candidates for next-generation uncooled blackbody-sensitive infrared photodetectors.

Te/SnS2 tunneling heterojunctions as high-performance photodetectors with superior self-powered properties

“…2D tellurium (Te) is a p-type material with a thickness-dependent bandgap (0.35–1.04 eV). 31 It has many intriguing properties, such as excellent photoresponse to infrared irradiation, 29,30 ambipolar electrical transport behavior, 31 high field-effect hole mobility exceeds 800 cm 2 V −1 s −1 , 32 and superior air stability enabled by the inherent chiral-chain structure along the c -axis. On the other hand, tin disulfide (SnS 2 ) is an intrinsic n-type semiconductor material with an indirect bandgap of 2.07 eV.…”

“…4 Furthermore, self-powered photodetectors can detect light without an external power supply, which has important applications in scenarios that have limited energy source. 24 The heterostructure-based self-powered photodetector, which can work well by the irradiation of light from ultraviolet (UV) [25][26][27][28] to infrared, 29 has been widely studied. However, due to the same above-mentioned reasons, the reported tunneling vdWHs exhibited zero-bias photoresponsivity below 1 A W À1 , which is too small for practical self-powered applications.…”

Polarity-Reversible Te/WSe2 van der Waals Heterodiode for a Logic Rectifier and Polarized Short-Wave Infrared Photodetector

“…A shift in the transistor threshold voltage could be observed from the upper part of Figure d, indicating that both photoconductive and photogating effects contribute to photocurrent generation . Particularly, the peak R reaches 1.9 × 10 3 A W –1 for near-infrared 980 nm, corresponding to a calculated D of 2.8 × 10 12 Jones (Figure S13 of the Supporting Information), among the highest reported in Te-based photodetectors. ,− Figure f presents partial time-resolved response curves under 980 nm with a switching frequency of 0.1 and 0.2 Hz for ∼280 continuous cycles, revealing a steady photoresponse characteristic. The full I ph – t spectrum and corresponding response time are shown in Figure S14 of the Supporting Information.…”

TexSe1–x Photodiode Shortwave Infrared Detection and Imaging

“…Elemental tellurium (Te), discovered by Muller Ferenc in 1782, [24] is such a promising infrared detection material with multiple intrinsic advantages compared to the other multicomponent infrared materials (especially the ternary MCT and InGaAs). For example: 1) it consists of only one element, beneficial to avoid the detrimental secondary phases and complex point defects; 2) the narrow bandgap of 0.35 eV enables a cutoff wavelength of 3.6 μm, [24][25][26][27][28] and the bandgap can be continuously tuned from mid-infrared to visual by incorporating the congeneric selenium (Se); [29,30] 3) Te has a low melting point of 450 °C and large saturated vapor pressure (100 Pa @ 450 °C), [31] suitable for thermal evaporation, which has the outstanding advantage in the preparation of large-scale uniform films; 4) Te can be crystallized at room temperature, making it possible to obtain high-quality film at low in situ or post-annealing temperature. [32,33] Te photodetectors thus could be compatible with CMOS readout circuitry; [34,35] and 5) Te enjoys large mobility of >1000 cm 2 V −1 s −1 , showcasing a very fast limiting response time of ≈10 ps (Supporting Information) and thereby enabling high-speed imaging.…”