Interface Engineering Ti₃C₂ MXene/Silicon Self‐Powered Photodetectors with High Responsivity and Detectivity for Weak Light Applications

Abstract

Interfacial engineering and heterostructures designing are two efficient routes to improve photoelectric characteristics of a photodetector. Herein, a Ti3C2 MXene/Si heterojunction photodetector with ultrahigh specific detectivity (2.03 × 1013 Jones) and remarkable responsivity (402 mA W−1) at zero external bias without decline as with increasing the light power is reported. This is achieved by chemically regrown interfacial SiOx layer and the control of Ti3C2 MXene thickness to suppress the dark noise current and improve the photoresponse. The photodetector demonstrates a high light on/off ratio of over 106, an outstanding peak external quantum efficiency (EQE) of 60.3%, while it maintains an ultralow dark current at 0 V bias. Moreover, the device holds high performance with EQE of over 55% even after encapsulated with silicone, trying to resolve the air stability issue of Ti3C2 MXene. Such a photodetector with high detectivity, high responsivity, and self‐powered capability is particularly applicable to detect weak light signal, which presents high potential for imaging, communication and sensing applications.

A porous GaN/MoO3 heterojunction for filter-free, ultra-narrowband ultraviolet photodetection

“…14,34,35 Specific detectivity is a description of the ability of a PD to detect weak signals in a noisy environment, which is evaluated using eqn (3). 36 where I d is the dark current, λ and e are the irradiation light wavelength and the electronic charge, respectively, P represents the light density, and A is the effective device area.…”

Patterning of Wafer‐Scale MXene Films for High‐Performance Image Sensor Arrays

“…[39] Our photodetectors fabricated on the same substrate also show good uniformity, which is essential for large-scale integration (Figures S19 and S20, Supporting Information). We compared its detectivity and L-to-D current ratio with previously reported results [33][34][35][36][37][38][39][40][41][42][43][44] and found that it had the ultrahigh detectivity and light-to-dark current ratio (Figure 2e).…”

“…Figure 2d shows rise and fall times of 9.53 and 14.26 µs, respectively. The constructed device responds faster than most MXene detectors [32][33][34][35][36][37][38] which can be further improved by increasing the laser frequency and bandwidth of measure equipment, reducing the capacitance of the substrate and using RF measurement. [39] Our photodetectors fabricated on the same substrate also show good uniformity, which is essential for large-scale integration (Figures S19 and S20, Supporting Information).…”

溶液法制备硅/SnCl2处理的Ti3C2TxMXene肖特基结 太阳电池

“…On the other hand, as one family of advanced two-dimensional (2D) materials, MXenes have gained extensive attention because of their similar properties to graphene including excellent electrical and optical properties [27][28][29][30][31][32][33][34]. Moreover, the work function (WF) of MXenes can be easily tuned in a broad range, e.g., from <2 eV to >6 eV for the Ti 3 C 2 T x MXene by adjusting the surfaceterminating groups [35][36][37][38], indicating the potential as a carrierselective material [39,40]. In addition, abundant raw materials can be used to produce high-quality MXenes just by the costeffective wet-etching method [41][42][43][44][45].…”