Stable, Fast UV–Vis–NIR Photodetector with Excellent Responsivity, Detectivity, and Sensitivity Based on α-In₂Te₃ Films with a Direct Bandgap

Abstract

Photoelectric conversion is of great importance to extensive applications. However, thus far, photodetectors integrated with high responsivity, excellent detectivity, large phototo-dark current ratio, fast response speed, broad spectral range, and good stability are rarely achieved. Herein, we deposited large-scale and high-quality polycrystalline indium sesquitelluride (α-In2Te3) films via pulsed-laser deposition. Then, we demonstrated that the photodetectors made of the prepared α-In2Te3 films possess stable photoswitching behavior from 370 to 1064 nm and short response time better than ca. 15 ms. At a source-drain voltage of 5 V, the device achieves a high responsivity of 44 A/W, along with an outstanding detectivity of 6 × 10(12) cm H(1/2) W(-1) and an excellent sensitivity of 2.5 × 10(5) cm(2)/W. All of these figures-of-merit are the best among those of the reported α-In2Te3 photodetectors. In fact, they are comparable to the state-of-the-art commercial Si and Ge photodetectors. For the first time, we established the theoretical evidence that α-In2Te3 possesses a direct bandgap structure, which reasonably accounts for the superior photodetection performances above. Importantly, the device exhibits a good stability against the multiple photoswitching operation and ambient environment, along with no obvious voltage-scan hysteresis. These excellent figures-of-merit, together with the broad spectral range and good stability, underscore α-In2Te3 as a promising candidate material for next-generation photodetection.

Extremely high-performance visible light photodetector in the Sb2SeTe2 nanoflake

“…Detectivity, that is an important figure-of-merit in evaluating the ability of a photodetector to detect weak signal, is another important indices used to characterize the performance of photodetectors33. The specific detectivity ( D * ) is calculated through the relation:…”

An Innovative Postdeposition Annealing Approach Producing Centimeter‐Scale In2O3/In2(TeO3)3 Bulk Heterojunction Thin Film for Room‐Temperature Persistent Photoconductivity

“…[28] Then, the as-deposited In 2 Te 3 thin films were transferred into a tube furnace and annealed according to a programmed procedure described below. [28] Then, the as-deposited In 2 Te 3 thin films were transferred into a tube furnace and annealed according to a programmed procedure described below.…”

“…In this contribution, as is schematically shown in Figure 1a,b, we exploited pulsed-laser deposition (PLD), an efficient, versatile, and large-scale deposition approach, [28][29][30][31][32][33][34][35][36][37] for the production of centimeter-scale In 2 Te 3 thin films, followed by a postdeposition annealing treatment in ambient environment. For the first time, we achieved the centimeter-scale inorganic bulk heterojunction thin film, hybrid In 2 O 3 /In 2 (TeO 3 ) 3 system.…”

“…Therefore, they hold great potential for practical applications. [28] Second, the thickness of the film decreases after annealing. They both comprise numerous small nanoparticles, revealing polycrystalline morphology.…”

2D Metal Chalcogenides for IR Photodetection

“…In the family of 2D group IIIA metal chalcogenides, 2D In‐based chalcogenides including In 2 S 3 , In 2 Se 3 , In 2 Te 3 , and InSe, have shown great promise in IR photodetection applications. As shown in Figure a,b, our group has successfully synthesized ultrathin 2D β‐In 2 S 3 by improved space‐confined CVD method and has explored the broad detection up to 900 nm .…”