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Much attention has been paid to the photoresponse of vanaduim oxide (VOx) and amorphous silicon based microbolometer for long-wavelength infrared detection under un-cooled operation condition in recent decades. However, the outstanding physical and chemical properties of graphene and reduced graphene oxide (rGO) stimulate their potential for use in light-sensitive applications. Much less attention has been paid to investigate the performance on long-wavelength infrared detection of microbolometer using reduced graphene oxide/SiNx/vanadium oxide composite films deposited on under room temperature operation. In the research, we have proposed the novel microbolometer based on VOx/SiNx/rGO composite films replace the as-deposited VOx based microbolometer. It is noted that such extraordinary properties (high responsivity: 18,130 V/W and low NETD: 43.32 mK) of the VOx/SiNx/rGO composite presented here encourage us to contemplate on this protocol for next generation optoelectronic device engineering for infrared detection.

Various tantalum (Ta)-doped vanadium oxide (VOx:Ta) films with various Ta doping contents were deposited on the Si substrates as the sensitive layer of the floating-type microbolometers using a magnetron radio frequency (RF) co-sputtering system. The vanadium (V) target and the tantalum pentoxide (Ta2O5) target were used to deposit the VOx:Ta films. To improve the microbolometer responsivity by effectively reducing the thermal loss from the Si substrates, the floating-type microbolometers were fabricated using bulk micromachining technique. From the X-ray photoelectron spectroscopy (XPS) spectra, except the V2O5 and V6O13, the lower oxygen state of VOx films, such as VO2 and V2O3, were also obtained by doping Ta into the VOx films. Consequently, compared with the VO2 microbolometers, the VOx:Ta microbolometers could operate at a higher operating temperature range. The temperature coefficient of resistance (TCR) and the resistivity of the VOx:Ta (Ta content of 7.63%) films measured by four point probe measurement in heating system were −3.47%/K and 9.32 Ω-cm, respectively. The Ta-doped VOx microbolometer revealed a higher responsivity of 341 kV/W compared with 106 kV/W of the undoped VOx microbolometer.

GaSb/GaAs quantum dots (QDs) and quantum rings (QRs) are investigated. By using periodical growth interrupts, precise coverage control can be achieved for GaSb QD growth by using a single Ga source. With direct As irradiation to the substrate surface during the post soaking time, the soaking time can be effectively reduced while full ring morphologies and room-temperature QR luminescence can still be obtained by using this method.

This paper focuses on the high energy proton irradiation effect of InAs/GaAs multilayers quantum-dot (QD) wafer and photodetector. With high energy proton path simulation, the releases of proton energy and trap distribution in QD multilayers are predicted well. Treated by 1 and 3 MeV protons, all protons almost penetrate the multilayers of QD structures and stop deeply in GaAs substrate. InAs QD multilayer structures/Infrared photodetector have been irradiated by protons with different energies (1 and 3 MeV) and doses (1 × 10 9 ∼ 1 × 10 13 protons/cm 2 ). The photoluminescence (PL) and photoresponsivity (PR) spectrum of samples were measured and discussed with as grown and post irradiation.

I – V characteristics of the unpassivated InAs p–i–n diodes with various i-layer thickness have been systematically studied. At the same reverse bias of −0.5 V, the reverse current density is −0.83 and −0.18 A/cm 2 for the p–n diodes and p–i–n diodes with a 0.72-μm-thick i-layer, respectively. It is obvious that the surface shunt and bulk leakage current are dramatically decreased owing to increasing of the i-layer thickness between p and n layers of InAs p–n junction. Meanwhile, an odd current–temperature behavior; the reverse-bias current decreases with increasing temperature, has been observed in the InAs p–i–n photodetector with a 0.72-μm-thick i-layer. Below 90 K, the photocurrent generated by the background thermal radiation should dominate the I – V characteristics of the p–i–n diode and the photocurrent increases a little as temperature drops due to the improvement of minority carrier diffusion length.