Broadband Photodetector Based on Inorganic Perovskite CsPbBr₃/GeSn Heterojunction

Abstract

in range of short-wave-infrared (SWIR) and the low responsivity in visible light. Photodetectors with active layers of traditional semiconductor materials, such as germanium (Ge), [9] indium gallium arsenide (InGaAs) [10,11] and mercury cadmium telluride (HgCdTe), [12] can realize a high performance in infrared band. But, the response for visible light of these detectors are extremely poor, which are limited by the short penetration length of visible light and low collection efficiency of photo-generated carriers. Compared with Si, Ge, InGaAs, or HgCdTe, the perovskite shows great potential in visible light response and many applications have been reported, such as solar cells [13][14][15][16][17][18][19] and photodetectors. [20][21][22][23] However, it is difficult to produce perovskite with narrow bandgap and its absorption cutoff wavelength can hardly extend longer than 1000 nm. Therefore, a hybrid structure combining perovskite and traditional semiconductor materials is one of a promising alternative to realize a high performance broadband photodetector.Previously, photodetector based on perovskite with Si, [27] Ge, [28] ZnO [29,30] or PbSe, [31] CuInSe 2 , [32] have been successfully demonstrated, and the photo-response can be covered from about visible region to near infrared region. [33] A brief summary of comparison of various photodetectors is shown in Table S1 (Supporting Information). For example, a solution-processed, high-performance broadband (300-1100 nm) photodetectors based on double active layers incorporating narrow-bandgap CuInSe 2 (CISe) quantum dots (QDs) and halide perovskite are devised by Guo et al. [30] Previously, our group has demonstrated the organic-inorganic perovskite MAPbI 3 /Ge heterojunction Photodetectors with broadband response spectrum have attracted great interest in many application areas such as imaging, gas sensing, and night vision. Here, a high performance broadband photodetector is demonstrated with inorganic perovskite CsPbBr 3 /GeSn heterojunction, detection range can be covered from 450 to 2200 nm. The responsivity of heterojunction device can achieve as high as 129 mA W −1 under illuminated light of 532 nm, which is 4.92 times larger than that of a GeSn based device. As the CsPbBr 3 can also act as anti-reflective coating for infrared wavelength, the infrared band responsivity at wavelength of 2200 nm can also be raised by 1.42 times. In addition, the device with all inorganic components is showed good stability, while keeping in the dry environment, the device can sustain its 90% original after 550 h storage. These results show the inorganic perovskite/GeSn heterojunction device is of great potential in broadband photodetection with high responsivity.

A high-responsivity CsPbBr3 nanowire photodetector induced by CdS@CdxZn1−xS gradient-alloyed quantum dots

“…5(c). 13,15,28,38,46,[59][60][61]66,67,69,[71][72][73] The detailed performances of related photodetector devices are listed in Table S2 (ESI †). Compared with the most carefully designed individual CsPbBr 3 wire and hybrid photodetectors, the performance of our photodetectors modified with QDs has remarkable advantages.…”

“…The photoelectric conversion efficiency obtained in this work under a 5 V bias voltage is much greater than that of most present CsPbBr 3 -based photodetectors, even at a much higher bias voltage. 13,38,[59][60][61][64][65][66][67][68][69][70][71][72][73][74][75] In addition, the detectivity (D*) of the CdS@Cd x Zn 1Àx S gradient-alloyed QD-decorated CsPbBr 3 photodetector is increased to 1.62 Â 10 13 Jones, and the response time is reduced to 330 ms. In consequence, a physical model based on band energy theory was developed to illustrate the physical mechanism of these unique enhancement phenomena.…”

Hybrid Halide Perovskite‐Based Near‐Infrared Photodetectors and Imaging Arrays

“…With a bandgap of ≈1.1 eV and the advantage of mature processing techniques, silicon has been widely applied to integrate with perovskites for highly sensitive and broadband light detection. [38,165,[177][178][179][180]182] Lin-Bao Luo, Yu-Cheng Wu, and co-workers reported a sensitive NIR PD through coating a vertical p-type silicon nanowire array (an average length of ≈15 µm and an average diameter of ≈140 nm) with a Cs-doped FAPbI 3 perovskite layer (40-50 nm thickness). [38] The silicon nanowire/ perovskite core-shell heterojunction NIR photodiode shows the spectral detection region from 300 to 1200 nm with the maximum sensitivity at around 850 nm.…”

“…MAPbI 3 /SWCNTs/NDI-DPP 375-1400 150 @ 1064 nm 2 × 10 12 @ 920-940 nm a) ≈20% @ 920-940 nm ->90 c) 4.32/12.16 [173] MAPbI 3 /PTB7-Th/IEICO-4F 340-940 518 @ NIR >10 10 @ 340-940 nm b) >70% --500/510 [174] MAPbI 3 /IEICO 300-900 140 @ 820 nm 7.37 × 10 11 @ 820 nm b) 30% @ 800-900 nm -192 c) -/0.027 [175] MAPbI 3 /F8IC:PTB7-Th 300-1000 370 @ 870 nm 2.3 × 10 11 @ 870 nm b) 54% @ 850 nm -191 c) 35/20 [176] Si/MAPbBr 3 single crystal 405-1064 ≈5 @ 1064 nm ≈2 × 10 10 @ 1064 nm a) ---0.52/2.44 [177] MAPbI 3 /Si-NPA 400-1050 8.13 @ 780 nm 9.74 × 10 12 @ 780 nm a) ---253.3/230.4 [178] CsPbBr 3 /GeSn 450-2200 ≈4.7 @ 2200 nm -----/26 [179] MAPbI 3 /Si 400-1200 18.4 @ 970 nm 1.8 × 10 12 @ 970 nm a) 23.5% --- [180] MAPbI 3 /DPP-CNTVT 400-980 500 @ 720 nm 10 14 @ 720 nm a) ≈90 @ 720 nm -265 c) 0.27/0.21 [181] Photoconductors MAPbI 3 400-1000 ≈4 × 10 3 @ 800 nm -≈600% @ 800 nm --39/1.9 [41] MAPbI 3 400-1064 ≈150 @ 820 nm (MAPbI 3 ) -≈22% @820 nm --1.2 × 10 5 /8 × 10 4 [45] MAPbI 3 /PDPP3T 300-940 154 @ 835 nm 5.5 @ 937 nm 8.8 × 10 10 @ 835 nm 3.2 × 10 9 @ 937 nm b)…”

High performance of a broadband room-temperature Si detector beyond the cut-off wavelength

“…1–5 However, the lack of suitable materials is the major obstacle for high-performance broadband detectors based on photoconductive and photovoltaic effects due to the bandgap limitation. Only a few narrow bandgap or zero bandgap materials have achieved broadband response using the photovoltaic or photothermal effect, for example black phosphorus, 6 Bi 2 O 2 Se, 7 and inorganic perovskite CsPbBr 3 /GeSn heterojunctions, 8 but there are serious problems such as material instability, long response time and complicated fabrication process.…”