排序方式: 共有38条查询结果,搜索用时 453 毫秒
1.
J. R. Lindle W. W. Bewley I. Vurgaftman J. R. Meyer J. L. Johnson M. L. Thomas W. E. Tennant 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):558
A self-referencing, optical modulation technique was used to measure the negative luminescence efficiencies of an array of mid-wave infrared HgCdTe photodiodes with cutoff wavelength 4.6 μm as a function of sample temperature. The internal efficiency at a wavelength of 4 μm was 93% at 295 K, and nearly independent of temperature in the 240–300 K range. This corresponds to an apparent temperature reduction >50 K at room temperature and >30 K at 240 K. Moreover, the reverse-bias saturation current density was only 0.13 A/cm2. The measured transmission and emission spectra were simulated using empirical HgCdTe absorption formulas from the literature. 相似文献
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The article concerns heterojunction resonant cavity-enhanced (RCE) Schottky photodiodes with GaAs in the absorption layer. The quantum efficiency and linear pulse response have thoroughly been analysed. For the first time, the response of a heterojunction photodiode has been modelled by the phenomenological model for a two-valley semiconductor. The results obtained have shown that the satellite valleys, as well as the parasitic time constant, significantly influence the response and, accordingly, have to be taken into account when analysing and optimizing RCE photodetectors. 相似文献
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J. Rutkowski P. Madejczyk A. Piotrowski W. Gawron K. Jóźwikowski A. Rogalski 《Opto-Electronics Review》2008,16(3):321-327
The performance of dual waveband HgCdTe photodiodes fabricated using metaloorganic chemical vapour deposition operated at
high temperatures is presented. The effect of additional separating layer on the quantum efficiency and cross-talk of the
photodiodes is analyzed. The photodiodes with cutoff wavelengths up to 6 μm, good R0A product, and high quantum efficiency at 200 K have been demonstrated. The temperature dependence of the differential resistance
is discussed. It is shown that the multilayer heterojunction P-n-N-n-P structure operating in a simultaneous mode has better
performance than a structure operating in a sequential mode. 相似文献
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An electro-optical technique is described for the measurement of the size distribution of particles from 2.5 μm upwards, in a flow. The apparatus utilizes a white light source, a photodiode array and particle-sizing electronics. The data acquisition system is a multichannel analyser or a microcomputer. This device is an extension to the flow case of a previous device designed for static size analysis, and a critical comparison with size acquisition systems commercially available is given. Shape of particles and outline of waveform during particle detection are discussed. 相似文献
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Optical properties of the silicon photodiodes are investigated in the visible spectral regime. Non-linearity measurement standard was established by using Hamamatsu S1337-11 type windowless silicon photodiode whose non-linearity value was found to be better than 6×10−5 at photocurrent level of 10−9 to 10−4 A. Temperature effects on the spectral responsivity for S1337-11, S1337-1010BQ and S1227-1010BQ type photodiodes were analyzed between 20°C and 40°C at 488.1, 514.7 and 632.8 nm vacuum wavelengths. The spatial uniformities of the responsivity for three type photodiodes are performed with a laser beam having 1 mm diameter by using home made two-axis micro translation system. Results of the reflectance measurements for three elements of reflection-based trap detectors were compared with the predicted values obtained from Fresnel equations. 相似文献
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Ardalan Armin Mike Hambsch Il Ku Kim Paul L Burn Paul Meredith Ebinazar B Namdas 《Laser \u0026amp; Photonics Reviews》2014,8(6):924-932
Inorganic semiconductor‐based broadband photodetectors are ubiquitous in imaging technologies such as digital cameras and photometers. Herein a broadband organic photodiode (OPD) that has performance metrics comparable or superior to inorganic photodiodes over the same spectral range is reported. The photodiode with an active layer comprised of a poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)]:[6,6]‐phenyl‐C71‐butyric acid methyl ester bulk heterojunction blend had a dark current < 1 nA/cm2, specific detectivity of ∼1013 Jones, reverse bias −3 dB frequency response of 100 kHz to 1 MHz, and state‐of‐the‐art Linear Dynamic Range for organic photodiodes of nine orders of magnitude (180 dB). The key to these performance metrics was the use of a thick junction (700 nm), which flattened the spectral response, reduced the dark current and decreased performance variations. The strategy also provides a route to large area defect free “monolithic” structures for low noise integrated photo‐sensing, position determination, or contact, non‐focal imaging. 相似文献
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A. Rogalski 《Opto-Electronics Review》2008,16(4):458-482
Third-generation infrared (IR) systems are being developed nowadays. In the common understanding, these systems provide enhanced
capabilities-like larger numbers of pixels, higher frame rates, and better thermal resolution as well as multicolour functionality
and other on-chip functions. In this class of detectors, two main competitors, HgCdTe photodiodes and quantum-well photoconductors,
have being developed.
Recently, two new material systems have been emerged as the candidates for third generation IR detectors, type II InAs/GaInSb
strain layer superlattices (SLSs) and quantum dot IR photodetectors (QDIPs).
In the paper, issue associated with the development and exploitation of multispectral photodetectors from these new materials
is discussed. Discussions is focused on most recently on-going detector technology efforts in fabrication both photodetectors
and focal plane arrays (FPAs). The challenges facing multicolour devices concerning complicated device structures, multilayer
material growth, and device fabrication are described. 相似文献
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