Responsivity

About: Responsivity is a research topic. Over the lifetime, 9918 publications have been published within this topic receiving 186118 citations.

Electrical and optical properties of infrared photodiodes using the InAs/Ga1−xInxSb superlattice in heterojunctions with GaSb

Abstract: The InAs/Ga1−xInxSb strained‐layer superlattice (SLS) holds promise as an alternative III–V semiconductor system for long wavelength infrared detectors. In this article, we present the first investigation, to the best of our knowledge, of heterojunction photodiodes using this new material. The devices were grown by molecular beam epitaxy on GaSb substrates, and are comprised of a 38 A InAs/16 A Ga0.64In0.36Sb SLS used in double heterojunctions with GaSb contact layers. The structures were designed to optimize the quantum efficiency while minimizing transport barriers at the heterointerfaces. The photodiodes are assessed through the correlation of their performance with the SLS material quality and the detector design. X‐ray diffraction, absorption, and Hall measurements are used to determine the SLS material properties. The electrical and optical properties of the photodiodes are determined using current–voltage and spectral responsivity measurements. At 78 K, these devices exhibit rectifying electrical behavior and photoresponse out to a wavelength of 10.6 μm corresponding to the SLS energy gap. The responsivity and resistance in these thin‐layered (0.75 μm), unpassivated photodiodes result in a detectivity of 1×1010 cm √Hz/W at 8.8 μm and 78 K. Based upon the performance of these devices, we conclude that high‐sensitivity operation of long‐wavelength photovoltaic detectors at temperatures well in excess of conventional III–V band gap‐engineered systems, and potentially in excess of HgCdTe, is feasible using this material system.

Ultraviolet photoconductive detector with high visible rejection and fast photoresponse based on ZnO thin film

Abstract: In this study, metal–semiconductor–metal (MSM) photoconductive detector was fabricated on c -axis preferred oriented ZnO film prepared on quartz by radio frequency magnetron sputtering. With the applied bias below 3 V, the dark current was below 250 nA. The typical responsivity peaked at around 360 nm, and had values of 30 A/W. In addition, the UV (360 nm) to visible (450 nm) rejection ratio of around five orders could be extracted from the spectra response. Furthermore, the transient response measurement revealed fast photoresponse with a rise time of 20 ns.

Extended performance GeSn/Si(100) p-i-n photodetectors for full spectral range telecommunication applications

Abstract: First-generation n-i-GeSn/p-Si(100) photodiode detectors with Ge0.98Sn0.02 active layers were fabricated under complementary metal oxide semiconductor compatible conditions. It is found that, even at this low Sn concentration, the detector quantum efficiencies are higher than those in comparable pure-Ge device designs processed at low temperature. Most significantly, the spectral range of the GeSn device responsivity is dramatically increased—to at least 1750 nm—well beyond the direct band gap of Ge (1550 nm). This allows coverage of all telecommunication bands using entirely group IV materials.

Colloidal Quantum Dots Intraband Photodetectors

Abstract: Photoconductivity is demonstrated with monodispersed HgSe colloidal quantum dots that are illuminated with radiation resonant with 1Se–1Pe intraband electronic absorption, between 3 and 5 μm. A doping of two electrons per dot gives the lowest dark current, and a detectivity of 8.5 × 108 Jones is obtained at 80 K. Photoluminescence of the intraband transition is also observed. The detector properties are discussed in terms of the measured photoluminescence quantum yield, the electron mobility in the 1Pe state, and the responsivity. The intraband photoresponse allows to fully harness the quantum confined states in colloidal nanostructures, extending the prior limited use of interband transition.