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The recent trend of combining perovskite with other materials to enhance optoelectronic performance has garnered significant interest. In this paper, MAPb0.9Sn0.1I3 and ZnO–MAPb0.9Sn0.1I3 photodetector were prepared by frequency magnetron sputtering and sol–gel spin-coating method. Hybrid heterojunction photodetectors have more beneficial optoelectronic performance compared to MAPb0.9Sn0.1I3 photodetector, due to the presence of built-in electric fields, which can suppress the recombination of electrons and holes. At 7 V bias conditions, the responsivities of MAPb0.9Sn0.1I3 photodetector were 0.022 and 0.015 A/W, and the responsivities of ZnO–MAPb0.9Sn0.1I3 photodetector were 0.39 and 0.99 A/W obtained under 350 and 850 nm illumination, respectively. The maximum external quantum efficiency reaches 144.47%, the detection rate was 5.53 × 1011 Jones and the light to dark ratio was 2.95 × 103 of ZnO–MAPb0.9Sn0.1I3 photodetector. This study provides a basis for the preparation of perovskite heterojunction photodetectors with high optoelectronic performance. High performance UV–vis–NIR photodetectors based on ZnO/organic–inorganic hybrid Sn–Pb hybrid perovskite heterojunction. [ABSTRACT FROM AUTHOR]

Interface engineering of the hole transport layer in CH3NH3PbI3 photodetectors has resulted in significantly increased carrier accumulation and dark current as well as energy band mismatch, thus achieving the goal of high-power conversion efficiency. However, the reported heterojunction perovskite photodetectors exhibit high dark currents and low responsivities. Herein, heterojunction self-powered photodetectors, composed of p-type CH3NH3PbI3 and n-type Mg0.2Zn0.8O, are prepared through the spin coating and magnetron sputtering. The obtained heterojunctions exhibit a high responsivity of 0.58 A/W, and the EQE of the CH3NH3PbI3/Au/Mg0.2Zn0.8O heterojunction self-powered photodetectors is 10.23 times that of the CH3NH3PbI3/Au photodetectors and 84.51 times that of the Mg0.2ZnO0.8/Au photodetectors. The built-in electric field of the p-n heterojunction significantly suppresses the dark current and improves the responsivity. Remarkably, in the self-supply voltage detection mode, the heterojunction achieves a high responsivity of up to 1.1 mA/W. The dark current of the CH3NH3PbI3/Au/Mg0.2Zn0.8O heterojunction self-powered photodetectors is less than 1.4 × 10−1 pA at 0 V, which is more than 10 times lower than that of the CH3NH3PbI3 photodetectors. The best value of the detectivity is as high as 4.7 × 1012 Jones. Furthermore, the heterojunction self-powered photodetectors exhibit a uniform photodetection response over a wide spectral range from 200 to 850 nm. This work provides guidance for achieving a low dark current and high detectivity for perovskite photodetectors. [ABSTRACT FROM AUTHOR]

The flexible ultraviolet (UV) photodetector (PD) has stable performance under mechanical flexibility to be applied on uneven surfaces. This provides a lot of freedom for redesigning photoelectric applications, so people highly regard it. We have studied the UV PD of Mg0.2Zn0.8O (MZO) film by radio frequency magnetron sputtering on flexible polyethylene terephthalate substrates to improve the photoelectric performance. Through the photoelectric performance analysis and comparison of the three PDs of MZO, ZnO1h/MZO, and ZnO2h/MZO, we found that the performance of PD containing ZnO film has been dramatically improved. Under 8 V bias, their responsivity was enhanced by 51 and 210 times, and the detectivity was enhanced by 2 orders of magnitude. Under 24 V bias, their responsivity is improved by 308 times and 1130 times, and external quantum efficiency is more than 1000%. Our findings provide a simple and easy way to achieve high-performance flexible MZO UV PD. [ABSTRACT FROM AUTHOR]

The formation of a broadband photodetector with high response, high sensitivity and controllable band is a major challenge to improve the application range of photodetectors. The integration of quantum dots and highly conductive materials is one of the important approach for the application of broadband photodetectors. In this work, ultraviolet–visible–near infrared (UV–Vis–NIR) sensitive PD consisting of ZnO film/PbS quantum dots (QDs) heterostructure was proposed. While forming a built-in electric field, the heterostructure also generates a barrier to prevent carrier recombination, so that the heterostructure PD has excellent photoresponse performance in the UV–Vis–NIR range, and the peak responsivity is increased by 550%. Increased from 0.974 mA/W to 6.332 mA/W, accompanied by obvious red shift, faster response and recovery speed compared to pure ZnO film PD. Different from other experiments, in order to make the performance gain of PbS QDs on ZnO film more obvious and intuitive, this article uses RF magnetron sputtering to prepare ultra-thin ZnO film, and discusses the impact of PbS QDs on the photoelectric properties of ZnO film more comprehensively and systematically. The performance of the broad spectrum in this experiment will be of great help to the research and application of ZnO PD in the future. • Ultraviolet–visible–near infrared (UV–Vis–NIR) sensitive PD consisting of ZnO film/PbS quantum dots (QDs) heterostructure was proposed. • While forming a built-in electric field, the heterostructure also generates a barrier to prevent carrier recombination, so that the heterostructure PD has excellent photoresponse performance in the UV–Vis–NIR range, and the peak responsivity is increased by 550%. Increased from 0.974 mA/W to 6.332 mA/W, accompanied by obvious red shift. • Faster response and recovery speed compared to pure ZnO film PD. • Discusses the impact of PbS QDs on the photoelectric properties of ZnO film more comprehensively and systematically. [ABSTRACT FROM AUTHOR]

A ZnO film with a c-axis preferred orientation was prepared on quartz using the radio frequency (RF) magnetron sputtering technique. Then, a metal-semiconductor-metal (MSM)-structured ultraviolet (UV) photodetector was fabricated on the film. It was found that the cutoff wavelength of the photocurrent redshifted from 361 to 379 nm when the bias increased from 5 to 30 V. The origin of the redshift has been interpreted in terms of a qualitative model considering the declining band gap caused by the bias. This method opens up the possibility of tuning the cutoff redshift of ZnO UV photodetectors. [ABSTRACT FROM AUTHOR]

In recent years, many studies have shown that nanostructures have an excellent gain effect on the performance of photodetectors (PDs). In this paper, Cu 2 O and ZnO was prepared by electrochemical and magnetron sputtering methods respectively, then the ZnO nanowire arrays (NWAs) were grown on Cu 2 O/ZnO PD by hydrothermal method. After growing ZnO nanowires (NWs), the responsivity of the Cu 2 O/ZnO PD was increased by about 16 times, and the absorption of light by PD was also greatly improved, indicating that the introduction of the NWs can effectively improve the absorption and utilization of the light by the Cu 2 O/ZnO PD. Moreover, the built-in electric field of Cu 2 O/ZnO can effectively separate electron-hole pairs and inhibit their recombination. The detection sensitivity of Cu 2 O/ZnO/ZnO NWs PD is increased by nearly 5 times, which proves that ZnO NWs have a remarkable improvement for heterojunction PDs. • Cu 2 O/ZnO/ZnO NWs PD was prepared by electrochemical method, magnetron sputtering method and hydrothermal method, respectively. • The introduction of the ZnO NWs can effectively improve the absorption and utilization of light to the Cu 2 O/ZnO PD. • ZnO NWs work with built-in electric field to enhance detector optoelectronic performance together. • This structure realizes the heterogeneous contact of p-Cu 2 O/n-ZnO, and makes full use of the good gain effect of ZnO NWs. [ABSTRACT FROM AUTHOR]

Abstract: Zinc oxide (ZnO) thin films have been grown on quartz substrates by using the radio frequency (RF) magnetron sputtering technique with different sputtering power, which was adjusted widely from 10 to 200W. It was found that the sputtering power play an important role in the growth process of the film. The characteristic features of crystallinity, absorption and photoluminescence (PL) were examined. Furthermore, the surface morphology of the films was also observed by using atomic force microscopy (AFM). Upon increasing the power during the growing process, the films deposited at a RF power of 150W showed the best crystal quality and optical properties. The inflection point at 150W is detectable. This tendency is estimated to result from the enhancing of the particles sputtered from the ZnO target induced by the enlarging power. These results demonstrate that there is an optimal power operating window for sputtering technique. The physical mechanism for this has been explained by a straightforward qualitative model and dynamics equations. [Copyright &y& Elsevier]

• High Mg-content single-phased wurtzite Mg 0.51 Zn 0.49 O films realized by a facile RF magnetron sputtering technique on quartz (SiO 2) substrates. • The solar-blind and visible-blind dual-band UV PDs based on W-Mg 0.51 Zn 0.49 O films heteroepitaxial growth on ZnO buffer layer (30 min) exhibited significantly enhanced properties especially the specific detectivity (1012 Jones) in solar-blind region. • The performances improvement through adhesion strength between W-Mg 0.51 Zn 0.49 O and ZnO BL provide a feasible way to improve the detection ability of solar-blind region in dual-band UV PDs. High Mg-content single-phase wurtzite Mg 0.51 Zn 0.49 O (W-Mg 0.51 Zn 0.49 O) films were realized by radio frequency (RF) magnetron sputtering technique on quartz (SiO 2) substrates. The metal-semiconductor-metal (MSM) solar-blind (SB) and visible-blind (VB) dual-band ultraviolet (DB-UV) photodetectors (PDs) were also fabricated based on heteroepitaxial growth of W-Mg 0.51 Zn 0.49 O films on ZnO buffer layer (BL) at different nucleation states. Under 270 nm of irradiation, the Au/Mg 0.51 Zn 0.49 O/ZnO (30 min) PD exhibited an optimal external quantum efficiency (EQE, 304.4%) and specific detectivity (1012), which indicated that the ZnO BL obtained with a 30 min treatment time was most efficient to improve the detection of SB-UV wavelength. The origin of these results was attributed to the contact area and adhesion strength between MgZnO and ZnO matrices. The results showed a feasible way to obtain high Mg-content wurtzite MgZnO alloys and performance improvement through ZnO BL, which is favorable to the applicability in SB/VB DB-UV PDs. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • ZnO MSM UV photodetector has been prepared by RF magnetron sputtering with different electrode spacings. • Both of the spectral responses show a saturation behavior dependence on the applied bias voltage. • The rise and fall ratios of responsivity in the narrower spacing are approximately three times faster than that in the wider one. • The origin has been interpreted considering the depletion width and electron-hole pairs separation. Abstract Metal-semiconductor-metal ultraviolet photodetector with different electrode spacing is fabricated on ZnO film, prepared by radio frequency magnetron sputtering technique on a quartz substrate. The responsivity of the ZnO photodetector increased with decreasing electrode spacing for the same bias. Meanwhile, both of the spectral responses show a saturation behavior due to the gain effect dependence on the applied bias voltage. Additionally, more attractive thing is that the rise and fall ratios of responsivity in the narrower spacing are approximately three times faster than that in the wider one. A physical mechanism primary focused on depletion width and electron-hole pairs is given to explain the above results. It is demonstrated that a straightforward way to enhance the responsivity of ZnO photodetectors for application is with different electrode spacings. [ABSTRACT FROM AUTHOR]

We fabricate Mg y Zn 1-y O metal-semiconductor-metal ultraviolet photodetectors by integrating Au electrodes (with different electrode spacings) onto a semiconductor film (Mg 0.20 Zn 0.80 O or Mg 0.42 Zn 0.58 O), prepared by the radio frequency magnetron sputtering deposition method. As expected, the Mg 0.20 Zn 0.80 O photodetectors have a larger responsivity than the Mg 0.42 Zn 0.58 O ones when the electrode spacing and bias voltage are constant. More interestingly, the responsivity of all the Mg y Zn 1-y O photodetectors increase with decreasing electrode spacing for the same bias. These results are well-understood in terms of the role played by the metal-semiconductor junction. [ABSTRACT FROM AUTHOR]