High-Performance Photodetectors Based on Single All-Inorganic CsPbBr₃ Perovskite Microwire

Abstract

In recent years, hybrid organic–inorganic perovskites have emerged as promising photosensing materials for next-generation solution-processed photodetectors, achieving high responsivity, fast speed, and large linear dynamic range. In particular, perovskite photoresistors possess low-cost fabrication and easy integration with low dimensional structures. However, a relatively large dark current is still limiting the further development of perovskite photoresistors. Herein, we introduce full-inorganic perovskite polycrystalline microwires for high-performance photodetection, in order to enhance the device stability. Furthermore, dark current and noise can be effectively suppressed by tuning the contacts. All-inorganic CsPbBr3 microwires with a number of nanocrystals on the wire surface are prepared by a simple, low-cost, two-step, solution-processed method at room temperature. Photodetectors based on this CsPbBr3 polycrystalline single microwire are assembled on indium tin oxide electrodes and demonstrate a decent responsivity up to 118 A/W and a fast response within 40 ms. In addition, such optimized photoresistors possess a fairly tiny dark current and noise, which result in an improved detectivity of >1012 Jones and demonstrate excellent characteristics to detect weak light.

ZnO‐Based Ultraviolet Photodetectors with Tunable Spectral Responses

“…We have noted that the specific detectivity values were calculated based on the responsivity and measured noise density. [33] Similar to the responsivity spectra, the NiO x /ZnO photodiodes showed relatively broader spectral response covering the range of 320-390 nm, and ZnO/PTAA photodiodes exhibited super-narrow spectral response with a FWHM of <25 nm. We also present the absorption coefficient (α) along with the D* spectra.…”

“…For comparison, we summarized the specific detectivity ( D * ) spectra of ZnO‐based UV photodiodes in Figure a,b. We have noted that the specific detectivity values were calculated based on the responsivity and measured noise density . Similar to the responsivity spectra, the NiO x /ZnO photodiodes showed relatively broader spectral response covering the range of 320–390 nm, and ZnO/PTAA photodiodes exhibited super‐narrow spectral response with a FWHM of <25 nm.…”

“…Figure b compares the J–V curves measured in dark and under white light illumination (100 mW cm −2 ). As one can see from Figure b, the ratio of I ph / I d reached 4650 at a small reverse bias of −1 V. Spectral responsivity ( R ) is a key parameter reflecting the detectable wavelength region and the efficiency of photon‐to‐electron conversion, which can be obtained bywhere P λ is the incident light power. Figure c displays the measured responsivity spectra versus wavelength under different bias voltages.…”

Atomic‐Layer Deposition‐Assisted Double‐Side Interfacial Engineering for High‐Performance Flexible and Stable CsPbBr3 Perovskite Photodetectors toward Visible Light Communication Applications

“…More importantly, the peak intensity ratio of (220) to (020) becomes much stronger after the incorporation of ALD-Al 2 O 3 modification layer, implying the preferred orientation growth along (220). [19] Inspired by the above literatures, it is proposed that the oxygen molecule in the precursor of ALD processed Al 2 O 3 layer contributes to forming high quality of CsPbBr 3 perovskite thin films.…”

“…The photoresponse speed is faster than most of previously reported perovskite-based devices. [19,23] Thanks to the interfacial passivation of Al 2 O 3 layer, the carrier trap states at the surface of CsPbBr 3 thin films could be repaired. [17] Meanwhile, the efficient charge separation at the CsPbBr 3 /TiO 2 interface further ensures fast photoresponse of ACT PDs.…”