Two-dimensional Ta2NiSe5/GaSe van der Waals heterojunction for ultrasensitive visible and near-infrared dual-band photodetector

Abstract

Dual-band photodetectors have attracted intensive attention because of the requirement of multiband information [such as visible (VIS) and near-infrared (NIR)] in multicolor imaging technology, in which additional information beyond human vision could assist object identification and navigations. The use of 2D materials can break the limitation of high cost of conventional epitaxial semiconductors and a complex cryogenic cooling system for multi-band detection, but there is still much room to improve the performance, especially in responsivity and signal noise ratio. Herein, we have fabricated a VIS-NIR dual-band photodetector based on a multilayer Ta2NiSe5/GaSe heterojunction. Benefiting from the type-II heterojunction, the separation of photo-induced carriers is naturally enhanced, which promotes the responsivity of this dual-band photodetector to 4.8 A W−1 (VIS) and 0.15 A W−1 (NIR) at room temperature with a suppressed dark current at ∼4 pA. Our work suggests that the Ta2NiSe5/GaSe heterostructure is a promising candidate for ultrasensitive VIS-NIR dual-band photodetection.

High-Gain MoS2/Ta2NiSe5 Heterojunction Photodetectors with Charge Transfer and Suppressing Dark Current

“…As shown in Figure b, the dependence of responsivity and detectivity is detected under 532 nm laser illumination at V ds = 3 V. Both R and D * decrease as the laser power density increases, which is consistent with the observed sublinear relationship between I ph and P , possibly related to the saturation of trap states . An extremely high responsivity of 515.6 A W –1 is obtained at the incident power density of 17.5 mW cm –2 , which is higher than that of all Ta 2 NiSe 5 -based phototransistors. − ,, Because of the low dark current of the heterojunction device (Figure S6a), the D * of the MoS 2 /Ta 2 NiSe 5 photodetector is up to the highest value of 3.1 × 10 13 Jones, which is comparable to that of the pure MoS 2 (∼3.9 × 10 12 Jones) and Ta 2 NiSe 5 devices (∼1.2 × 10 12 Jones). The D * of the heterostructure is superior to that reported in the MoS 2 /PdSe 2 photodetector (6.3 × 10 10 Jones), MoS 2 /MoTe 2 photodetector (1.4 × 10 8 Jones), and MoS 2 /GaSe photodetector (2.3 × 10 11 Jones) …”

“…41 An extremely high responsivity of 515.6 A W −1 is obtained at the incident power density of 17.5 mW cm −2 , which is higher than that of all Ta 2 NiSe 5 -based phototransistors. [15][16][17]46,47 Because of the low dark current of the heterojunction device (Figure S6a), the D* of the MoS 2 / Ta 2 NiSe 5 photodetector is up to the highest value of 3.1 × 10 13 Jones, which is comparable to that of the pure MoS 2 (∼3.9 × 10 12 Jones) and Ta 2 NiSe 5 devices (∼1.2 × 10 12 Jones). The D* of the heterostructure is superior to that reported in the MoS 2 /PdSe 2 photodetector (6.3 × 10 10 Jones), 49 MoS 2 / MoTe 2 photodetector (1.4 × 10 8 Jones), 48 and MoS 2 /GaSe photodetector (2.3 × 10 11 Jones).…”

Band-engineered dual-band visible and short-wave infrared photodetector with metal chalcogenide colloidal quantum dots

“…4 Dual-band visible and infrared photodetectors (PDs) that can process signals of visible and infrared wavebands afford more accurate and comprehensive images of detected objects than obtained via single-band detection, which improves the detection and identification ability of the system. 1,2,5,6 The mature semiconductors such as silicon (visible, VIS, 400-700 nm), InGaAs (short-wave infrared, SWIR, 1.5-1.7 mm), and HgCdTe (mid-infrared, MIR, 3-12 mm) are the primary optoelectronic material systems that cover the broadband sensing range. 4,7,8 However, when integrating materials with different energy gaps into the same PD pixel, the lattice mismatch and incompatible preparation processes hinder the realization of visible/infrared dual-band PDs.…”

“…4 Dual-band visible and infrared photodetectors (PDs) that can process signals of visible and infrared wavebands afford more accurate and comprehensive images of detected objects than obtained via single-band detection, which improves the detection and identification ability of the system. 1,2,5,6…”

“…18 Zhang et al employed two-dimensional materials of Ta 2 NiSe 5 and GaSe to construct a VIS-near infrared (NIR) dual-band photodetector with a heterogeneous structure. 5 Organic photovoltaic devices employing inexpensive, easily regulated polymer or small-molecule organic materials have shown promising optoelectronic applications. Lan et al reported a dual-band organic PD with a P3HT:PC 70 BM visible-light absorber/optical spacer/P3HT:PTB7-Th:PC 70 BM NIR light absorber configuration, which can operate in the NIR and visible spectral ranges.…”