China
Africa
Explore chapters and articles related to this topic
ZnBeMgO Alloys and UV Optoelectronic Applications
Published in Zhe Chuan Feng, Handbook of Zinc Oxide and Related Materials, 2012
Hsin-Ying Lee, Li-Ren Lou, Ching-Ting Lee
The solar-blind UV photodetectors have vast potential applications in the fields of solar astronomy, missile plume detection, space-to-space transmission, fire alarms, and combustion monitoring. Since the solar radiation component in the solar-blind spectrum range (220–280 nm) is absorbed by the atmosphere, hence a photodetector working in this range will not be interfered by the solar radiation [68]. For the solar-blind UV detector, its cutoff working wavelength should be shorter than 280 nm, corresponding to the bandgap wider than 4.4 eV. However, high-performance solar-blind ZnO-based photodetectors have not yet been obtained. Moreover, an external (reverse) bias is required to achieve high photoresponsivity for most ZnO/Si photodiodes.
GaN Nanoflowers
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Neha Aggarwal, Shibin Krishna, Govind Gupta
In recent times, the necessity to detect UV radiation (being the highly harmful and energetic radiation) has stimulated much interest in the field of research and development of UV PDs. There are a number of potential applications of UV PDs, such as, air/water purification, ozone layer monitoring, forest fire prevention, missile detection, submarine oil leakage monitoring, chemical sensing, interspace communication, etc. An ideal PD for such applications must possess high sensitivity, fast response, minimum noise, high detectivity, insensitive to temperature variations, long operating lifetime, high spectral selectivity, high radiation hardness, and low cost. However, the growing need of miniaturized and reliable UV detection systems for portable applications has driven the development of semiconductor-based UV PDs. Earlier, narrow bandgap semiconductors were first considered to perform UV detection, such as silicon and some III-V compounds. However, the well-established Si technology has some limitations in the UV region because filters are required to block low energy photons (visible and infrared light), and degradation is produced by highly energized UV photons (shorter device lifetime). Moreover, SiC-based photodiodes have a relatively narrow range of sensitivity, and GaP photodiodes have a good signal-to-noise ratio, but it is impossible to create solar-blind and visible-blind photodiodes based on them without using filters. To avoid the use of filters and achieve better device operation, UV detectors based on wide bandgap semiconductors have been studied during the last decade. The first GaN-based UV detector fabricated from as-deposited single-crystal GaN films was demonstrated in 1992 [42]. Thereafter, several research groups have contributed to the development of UV PDs.
GaN based semiconductors for future optoelectronics
Published in Jong-Chun Woo, Yoon Soo Park, Compound Semiconductors 1995, 2020
Danielle Walker, Patrick Kung, Adam Saxler, Xiaolong Zhang, Manijeh Razeghi, Holger Jürgensen
There is currently a need for ultraviolet (UV) detectors which have high responsivities and are solar blind. A few potential applications include the detection of spacecraft and the monitoring of combustion chambers, where it is desirable to detect UV radiation in a visible and infrared background. Gallium nitride (GaN) has a direct, wide bandgap (λg=365 nm) and is the ideal material for intrinsic UV detectors for wavelengths shorter than 365 nm.
Progress in semiconductor diamond photodetectors and MEMS sensors
Published in Functional Diamond, 2022
By depositing β-Ga2O3 on diamond, self-powered solar-blind photodetectors based on diamond/β-Ga2O3 heterojunctions was reported. Under zero bias, the photodetectors showed a peak responsivity of 0.2 mA W−1 at 244 nm and a sharp cutoff wavelength of 270 nm [77]. Other oxides/diamond heterojunctions were also reported to broaden the spectral response of diamond, such as by depositing TiO2 or NiO thin films on diamond [78,79]. Nevertheless, the interface of the heterojunctions should be investigated.