We present an approach for the highly sensitive photon detection based on quantum dots (QDs) operating at temperature of 77K. The structure is AlAs∕GaAs∕AlAs double barrier resonant tunneling diode combined with a layer self-assembled InAs QDs (QD-RTD). A rate 115 photons per second had induced 10nA photocurrent in this structure, corresponding to photoexcited carrier multiplication factor 107. This high achieved by dot memory effect and tuning QD-RTD structure.

In this letter, a beveled-mesa edge termination technology was developed to improve the performance of GaN pi-n ultraviolet avalanche photodiodes (APDs). Simulation results showed that is effective in reduction electric field at mesa sidewall. With photoresist thermal-reflow process, 12°-angle APDs were fabricated from homoepitaxial p-i-n structures on substrate. The most beneficial property uniform breakdown-characteristic compared vertical-mesa APDs. Record-high VBR uniformity 95.4 V ± 0.2...

We report the behaviour of dark current and gain characteristics Si- GaN-based avalanche photodiodes (APDs) irradiated by fast neutrons. For Si-based APDs, increases with increase neutron fluence, indicating that property has been seriously affected. The values APD slightly after irradiation a low fluence 1.0 × 1012 cm−2, while device exhibits degradation as to 1013 cm−2 or even above at high reverse bias voltage, unlike previous studies where only was observed. steep when approaching...

This paper reports a plasma post-treatment technique to improve the performance of GaN ultraviolet avalanche photodiodes (APDs). A BCl3-based post-etching was developed smooth roughened surface after inductively-coupled-plasma etching. Atomic-scale roughness around 0.278 nm rms and photoluminescence intensity more than doubled were achieved post-treatment. The smoothing applied fabrication process double-mesa structure APDs grown on sapphire substrate. Compared non-treated APDs, post-treated...

Quantum structure has been optimized for the excited state confinement to improve detector performance of quantum wells infrared (QWIP) and dots (QDIP). By energy band engineering, states in are easier be manipulated than case interband transition bulk material. Moreover, confined resonant tunneling diode shown its function amplify photo-excited carrier order 10⁷, which imply that a new high sensitivity will resulted from integration such amplification with inter-subband...

Recently the GaN/AlN multi-quantum-well structure avalanche photodiode (MAPD) has been demonstrated with PMT-like multiplication gain larger than 1E4. In this work, photocurrent of MAPD investigated and negative differential conductance (NDC) is found in characteristic MAPD. Through self-consistent calculation, conduction band discrete energy states each quantum well layer have obtained for The drop down align edge absorption around NDC peak voltage, so feature proposed as resonant tunneling...

APD based on AlN/GaN periodically stacked structure (PSS) has been proposed to obtain a high ionization coefficient ratio of more than 100 and record linear-mode gain 104. Here the full p-i-p-i-n SAM PSS is simulated discuss influence polarization effect which cannot be ignored. The dependence device performances parameters in studied detail, will helpful for design optimization APD.

We experimentally studied the photocurrent of AlAs/GaAs/AlAs double barrier resonant tunneling diode (RTD), which is composed an InAs layer self-assembled quantum-dots (QDs) on top AlAs layer. It found that charging quantum dots can effectively modulate carrier transport properties RTD. Moreover, we also current through a single energy level individual dot extremely sensitive to photo-excited holes bound nearby dot, and presence lowers electrostatic state. In addition, it observed increase...

The active photo-excited carrier has been identified in reverse biased quantum dot resonant tunneling diode (QDRTD) for light detection. QD is embedded on the AlAs/GaAs/AlAs double barrier part of material structure and found with strong charge memory effect. charged electrons forward bias storage maintained well until voltage peak. With this effect, holes are into QDs still influence behavior QDRTD at dark. Compared to illuminated bias, unambiguously as holes. potential profile also...

The influence of superlattice periods and well doping on the band structure distribution electrons for III-nitride intersubband photodetectors are theoretically studied. It is found that there more wells populated with increase concentration. This knowledge beneficial to improve absorption efficiency, providing theoretical supports optimal design photodetectors.

An investigation was made to observe the electrooptical effect of ER fluids prepared with starch and silicon oil through experiments, in which transmitted light intensity fluid samples different concentration were measured under varying external electric field. The results show that detected photocurrent increases first then decreases increasing field; sample higher reaching peak value requires a lower field, but it has an opposite for concentration. field better tunability refractive index than

The light response mechanism of quantum dot resonant tunneling diode (QDRTD) has been investigated experimentally. QDRTD is constructed by an InAs layer self-assembled quantum-dots (QDs) being placed on the top AlAs barrier layer. work bias device set in positive differential resistance region. It found that charging dots can effectively control carrier transport properties device. photo-excited holes lower electrostatic energy state. Thus, electrons emitter easily tunnel to collector, and...

Polarization is an important property of GaN/AlN multi-quantum-well (MQW) avalanche diode (MAPD) but has been ignored in recent analyses MAPD to simplify the Monte Carlo simulation. Here, photocurrent characteristics are investigated understand role polarization field MQW structure. Carrier multiplication AlN/GaN found as a result interfacial impact ionization not much helped from external instead considerably contributed by field. In addition, movement ionized electrons out quantum well...

The structure parameters of III-nitride double-step intersubband photodetectors are theoretically analyzed to ensure efficient extraction photo-excited electrons. results indicate that the polarization field in barrier layer behaves sensitive thickness well and step layers. In addition, reducing Al mole composition or properly increasing its will be helpful enhance electrons tunneling. This knowledge is beneficial design terahertz with high efficiency.

GaN APD with periodic ultra-thin AlN interlayers in multiplication region has been proposed to obtain a high gain at constant voltage mode. The influence of the on process was numerically simulated and analyzed. results predict that contains three different stages increase reverse voltage. experimental agree simulation very well 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> mode obtained.

Carrier transport through GaN/AlN periodically stacked structure photodiode (PSSPD) is investigated considering the polarization field in structure. The movement of electrons out quantum well found as Fowler-Nordheim tunneling process helped by AlN barrier. PSSPD influenced reverse GaN layer but could be suppressed external electric field. Different rates current increase are also predicted from analysis polarized band structure, which consistent with experimental results.

We report the behaviour of dark current and gain characteristics Si- GaN-based avalanche photodiodes (APDs) irradiated by fast neutrons. For Si-based APDs, increases with increase neutron fluence, indicating that property has been seriously affected. The values APD slightly after irradiation a low fluence 1.0×10 12 cm -2 , while device exhibits degradation as to 13 or even above at high reverse bias voltage, unlike previous studies where only was observed. steep when approaching breakdown...