High-performance UV Photodetectors Research Articles

Coupling of photoelectric and triboelectric effects as an effective approach for PZT-based high-performance self-powered ultraviolet photodetector

A high-performance self-powered UV photodetector (UV-SPPD) using a PZT film was fabricated and characterized. It has a dual sensing mechanism that relies on the joint properties of a photoelectric effect and a triboelectric effect on the surface of the ferroelectric material. The UV-SPPD exhibits excellent responsivity (15mAW−1), large detectivity (2×1010cmHz−1/2 W−1), a fast photo response time (<50ms), and good stability and repeatability. This work creates new opportunities for designing high-performance self-powered UV photodetectors and other tribotronic devices.

Multifunctional zinc oxide thin films for high-performance UV photodetectors and nitrogen dioxide gas sensors

Multifunctional use of ZnO thin film as NO2 gas sensor and UV photodetector.

A high-performance self-powered UV photodetector based on SnO2 mesoporous spheres @ TiO2

A novel self-powered UV photodetector (UVPD) based on the photoelectrochemical cell (PECC) has been constructed using the TiO2 coated SnO2 mesoporous spheres (SnO2-MS@TiO2). This self-powered UVPD displays a higher photocurrent density compared to the UVPD with the pure SnO2-MS. By means of external quantum efficiency (EQE), UV-vis absorption, and electrochemical impedance measurements, we scrutinize the intrinsic role of the TiO2 coating layer on the photocurrent enhancement. Under UV irradiation, this UVPD exhibits a high on/off ratio of 11519, a fast rise time of 0.007 s and decay time of 0.006 s, together with the excellent visible-blind characteristic and linear optical signal response. The self-powered photodetector is a promising candidate for application in high-sensitivity and high-speed UVPDs.

Ultraporous Electron-Depleted ZnO Nanoparticle Networks for Highly Sensitive Portable Visible-Blind UV Photodetectors.

A hierarchical nano- and microstructured morphology for visible-blind UV photo-detectors is developed, which provides record-high milliampere photocurrents, nanoampere dark currents, and excellent selectivity to ultralow UV light intensities. This is a significant step toward the integration of high-performance UV photodetectors in wearable devices.

Few-layer WO3 nanosheets for high-performance UV-photodetectors

High quality few-layer WO3 nanosheets were synthesized via chemical vapor deposition (CVD) route. The high-performance UV photodetectors were successfully fabricated based on these few-layer WO3 nanosheets, showing excellent optoelectronic performance with high sensitivity (293A/W), fast response speed(40ms), high on/off ratios(2000), high external quantum efficiency (EQE, 997%), excellent stability, reversibility. These unique characteristics of the WO3 photodetectors pave the way for the fabrication of multifunctional and high performance flexible photodetectors based on the layered semiconductor materials.

High-performance UV photodetectors and temperature-dependent photoluminescence of individual ZnO hexagonal-prism microwire

ZnO hexagonal-prism microwires (HPMs) with the average width of about 50 m have been fabricated by a floating zone method. Their structural, temperature-dependent photoluminescence (PL) and UV photoresponse based on an individual ZnO HPMs were systematically investigated. For the temperature-dependent PL properties, different transitions including free exciton emission, bound exciton emission and free-to-bound transition were clearly observed at 83 K. The individual ZnO HPM-based UV photodetector showed a response cut-off wavelength of 390 nm and an ultraviolet/visible ratio of about two orders of magnitude with an applied bias of 5 V. 2014 Springer-Verlag Berlin Heidelberg

ZnO homojunction ultraviolet photodetector based on p-type dual-doped film and n-type nanorods

ZnO:(Ag,N)/ZnO p–n homojunction was fabricated by depositing a ZnO:(Ag,N) film on vertically aligned ZnO nanorods (NRs). The homojunction is able to work as a self-powered device due to the photovoltaic effect, and the ZnO NRs play an important role in the photovoltaic conversion process. Current–voltage (I–V) characteristic shows a turn-on voltage of ∼3V and a rectification ratio of 1.3×102 at 5V. Spectral responsivity exhibits an UV-to-visible rejection ratio of 1×102. The photocurrent rise and decay times are 7 and 45ms, respectively. These results indicate the ZnO:(Ag,N)/ZnO homojunction is an attractive candidate for high-performance self-powered UV photodetectors.

High-performance self-powered UV photodetectors based on TiO2 nano-branched arrays

Nano-branched TiO2 arrays were fabricated on fluorine-doped tin oxide (FTO) glass by a facile two-step chemical synthesis process. Self-powered UV photodetectors based on photoelectrochemical cells (PECs) were assembled using these TiO2 nano-branched arrays as photoanodes. These visible–blind self-powered UV photodetectors exhibit high sensitivity and high-speed photoresponse. Compared with photodetectors based on bare TiO2 nanorod arrays, TiO2 nano-branched arrays show drastically improved photodetecting performance as photoanodes. The photosensitivity increases from 0.03 to 0.22 A W−1 when optimized nano-branched TiO2 arrays are used, corresponding to an incident photon-to-current conversion efficiency higher than 77%. The UV photodetectors also exhibit excellent spectral selectivity and fast response (0.05 s decay time). The improved performance is attributed to a markedly enlarged TiO2/electrolyte contact area and good electron conductivity in the one-dimensional, well-aligned TiO2 nanorod trunk.

Synthesis of Fe‐Doped ZnO Nanorods by Rapid Mixing Hydrothermal Method and Its Application for High Performance UV Photodetector

We have successfully synthesized Fe‐doped ZnO nanorods by a new and simple method in which the adopted approach is by using ammonia as a continuous source of OH− for hydrolysis instead of hexamethylenetetramine (HMT). The energy dispersive X‐ray (EDX) spectra revealed that the Fe peaks were presented in the grown Fe‐doped ZnO nanorods samples and the X‐ray photoelectron spectroscopy (XPS) results suggested that Fe3+ is incorporated into the ZnO lattice. Structural characterization indicated that the Fe‐doped ZnO nanorods grow along the c‐axis with a hexagonal wurtzite structure and have single crystalline nature without any secondary phases or clusters of FeO or Fe3O4 observed in the samples. The Fe‐doped ZnO nanorods showed room temperature (300 K) ferromagnetic magnetization versus field (M‐H) hysteresis and the magnetization increases from 2.5 μemu to 9.1 μemu for Zn0.99Fe0.01O and Zn0.95Fe0.05O, respectively. Moreover, the fabricated Au/Fe‐doped ZnO Schottky diode based UV photodetector achieved 2.33 A/W of responsivity and 5 s of time response. Compared to other Au/ZnO nanorods Schottky devices, the presented responsivity is an improvement by a factor of 3.9.

Ultraviolet photodetector with high internal gain enhanced by TiO_2/SrTiO_3 heterojunction

In this letter, TiO₂ nanocrystalline film was prepared on SrTiO₃ (001) substrate to form an n-n heterojunction active layer. Interdigitated Au electrodes were deposited on the top of TiO₂ film to fabricate modified HMSM (heterojunction metal-semiconductor-metal) ultraviolet photodetector. At 10 V bias, the dark current of the detector was only 0.2 nA and the responsivity was 46.1 A/W at 260 nm. The rise and fall times of the device were 3.5 ms and 1.4 s, respectively. The TiO₂/SrTiO₃ heterojunction contributed a lot to the high responsivity and reduced the fall time, which improved the device performance effectively. These results demonstrate the excellent application of TiO₂/SrTiO₃ heterojunction in fabricating high performance UV photodetectors.

Ultrahigh External Quantum Efficiency from Thin SnO2 Nanowire Ultraviolet Photodetectors

Thin SnO2 nanowires with uniform dia­meter and large surface-to-volume ratio are synthesized, and a single wire is used to fabricate a high-performance UV photodetector. An ultrahigh external quantum efficiency of 1.32 × 107 is achieved, which is about four orders of magnitude larger than that of conventional SnO2 photodetectors.

GaN Nanofibers based on Electrospinning: Facile Synthesis, Controlled Assembly, Precise Doping, and Application as High Performance UV Photodetector

Nitride nanofibers have been synthesized based on a simple electrospinning technique for the first time. No catalysts or templates are needed in this new synthetic method. Highly oriented GaN nanofiber arrays, as well as a high-performance UV photodetector based on single GaN nanofiber assembled FET devices, can be facilely fabricated using this technique. Precise doping of other elements into the GaN nanofibers is easy by this solution-based synthetic method.

A High Performance UV Photodetector from Thin Film Diamond

ABSTRACTThin film diamond has been used to fabricate a photodetector which displays high sensitivity to deep UV light, with an external quantum efficiency of greater than one, a dark current of less than 0.1nA and which is near ‘blind’ to visible light.