Enhanced UV–visible detection of InGaZnO phototransistors via CsPbBr₃ quantum dots

Abstract

Indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) exhibit high field-effect carrier mobility and low off-state current, which are attractive for high speed and low noise photodetectors and image sensor applications. However, with an optical band gap of ∼3.3 eV, the photodetection range of IGZO TFTs is limited to short wavelength ultraviolet (UV) light.Here, we demonstrate a simple approach to enhance the performance of IGZO-based phototransistors by incorporating layers of solution-processed perovskite quantum dots (QDs) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Owing to the fast transfer of photogenerated electrons by CsPbBr 3 QDs absorbing layer, the photoresponse of QD-decorated IGZO phototransistor is extended to the visible range (500 nm), and the responsivity and detectivity of QD-decorated device are more than two order higher than those of original IGZO TFTs. Moreover, the QD-decorated IGZO phototransistor also exhibits enhanced performance under UV light (350 nm), achieving a responsivity of 9.72 A W −1 , a detectivity of 2.96×10 12 Jones, and a light to dark current ratio in the order of 10 6 at a wavelength of 350 nm (a light intensity of 207.3 μW cm −2 ).

A Review of Phototransistors Using Metal Oxide Semiconductors: Research Progress and Future Directions

“…Similarly, the quantum dots (QDs)/metal oxide phototransistors could be easily modified photonic properties by controlling the size of QD particles. [ 129–134 ] For instance, Nathan et al. reported a QD/IGZO phototransistor for detecting visible light region as shown in Figure 12d.…”

Visible-light-stimulated synaptic InGaZnO phototransistors enabled by wavelength-tunable perovskite quantum dots

“…14 To extend its photodetection range, hybrid IGZO phototransistors with various light absorption layers like metal oxide semiconductors, polymer semiconductors and quantum dots have been reported. [15][16][17][18] Inorganic lead halide perovskite (CsPbX 3 , X ¼ Cl, Br, I) quantum dots (QDs), which possess higher stability than their thin-lm counterparts, have gained extensive research interest in the eld of light-emitting diodes and photodetectors. [19][20][21][22][23][24] Previously, we have shown enhancement in photoresponsivity by capping IGZO with perovskite QDs.…”

“…[19][20][21][22][23][24] Previously, we have shown enhancement in photoresponsivity by capping IGZO with perovskite QDs. 18 Perovskite QDs seem attractive enough in this case due to their tunable-wavelength capability. Previous reports have also recently addressed halide perovskite based photonic synapsis, which interestingly emulate both synaptic plasticity and learning processes.…”

Low-power driven broadband phototransistor with a PbS/IGO/HfO2 stack

“…19,20 The most studied channel materials in AOS-based phototransistors are amorphous indium-gallium-zinc oxide (IGZO) and zinc-oxide (ZnO). [21][22][23][24][25][26] However, their intrinsic large band gap (43 eV) allows for the detection of UV photons whereas visible light is hardly absorbed in AOS layer. [27][28][29] To offer a detection capability for visible light, a number of different absorption layers have been introduced into oxide TFTs, such as oxides, chalcogenides, organic materials, perovskites, and QDs.…”