Avalanche Breakdown Effects Research Articles

A polysilicon based bipolar-like avalanche light-emitting diode with an enhanced avalanche breakdown effect

The advantage of silicon-based avalanche N + P junction LEDs is that they are compatible with silicon CMOS processes and facilitate optoelectronic integration, but their relatively high operating voltage limits their applications. In view of this, we propose a polysilicon avalanche LED (light-emitting device) with a bipolar-like structure that has a different avalanche breakdown mechanism from that of a normal PN junction, achieving an operating voltage significantly lower than that of a conventional N + P LED. Five polysilicon avalanche LEDs with base lengths ranging from 4 µm to 10 µm have been fabricated and tested. They have proven to operate at voltages as low as about 6–7 V, while the conventional N + P LEDs used for comparison cannot operate below 9 V. We also observed that they have higher luminous efficiency than the conventional N + P LED. The luminous intensity of the bipolar-like LED with a base length of 4 μm is about 41 % higher than that of the conventional N + P LED at a power consumption of 0.4 W. This demonstrates the advantages of bipolar avalanche LEDs in all-silicon monolithic optoelectronic integration applications.

Breadboard of Microchip and Avalanche Photodiode in Linear and Geiger Mode for LiDAR Applications

This paper reports the implementation of two critical technologies used in LiDARs: 1) A microchip Q-switched laser breadboard and 2) breadboard of an Indium gallium arsenide avalanche photodiode working at 300 K with high reverse polarization voltages. Microchip Q-switched lasers are small solid state back pumped lasers, that can generate high energy short pulses. The implemented breadboard used an Erbium and Ytterbium co doped phosphate glass, a COMALO crystal with 98% (initial transparency) and an output coupler of 98% reflectivity. For the sensor test, a system for the simultaneous operation in vacuum and wide range of temperatures was developed. Avalanche photodiodes are reverse polarized photodiodes with high internal gain, due to their multiple layer composition, capable of building up high values of photocurrent from small optical signals by exploiting the avalanche breakdown effects. The test avalanche photodetector was assembled to be operated in two modes: Linear and Geiger mode, to achieve this behavior, a transimpedance amplifier circuit was implemented. These two technologies are critical for mobile LiDAR applications, due to its low mass and high efficiency. The paper describes the breadboard implementation method and sensor characterization at low temperature and high voltage (beyond breakdown voltage).

Breadboard of Microchip Laser and Avalanche Photodiode in Geiger and Linear Mode for LiDAR Applications

This paper reports the implementation of two critical technologies used in light detection and ranging for space applications: (1) a microchip Q-switched laser breadboard; (2) a breadboard of an indium gallium arsenide avalanche photodiode working at 292 K with high reverse polarization voltages. Microchip Q-switched lasers are small solid-state back-pumped lasers that can generate high-energy short pulses. The implemented breadboard used an erbium and ytterbium co-doped phosphate glass, a Co:Spinel crystal with 98% initial transparency, and an output coupler with 98% reflectivity. For the sensor test, a system for simultaneous operation in vacuum and a wide range of temperatures was developed. Avalanche photodiodes are reverse-polarized photodiodes with high internal gain due to their multiple layer composition, capable of building up high values of photocurrent from small optical signals by exploiting the avalanche breakdown effects. The test avalanche photodetector was assembled to be operated in two modes: linear and Geiger mode. The produced photocurrent was measured by using: (1) a passive quenching circuit; (2) a transimpedance amplifier circuit. These two technologies are important for mobile light detection and ranging applications due to their low mass and high efficiencies. The paper describes the breadboard’s implementation methods and sensor characterization at low and room temperatures with high bias voltages (beyond breakdown voltage).

High sensitive room temperature NO2 gas sensor based on the avalanche breakdown induced by Schottky junction in TiO2-Sn3O4 nanoheterojunctions

A novel sensor based on Schottky junction inducing avalanche breakdown effect in TiO 2 -Sn 3 O 4 nanoheterojunctions is assembled. High sensitivity for NO 2 gas sensing is demonstrated at room temperature. TiO 2 -Sn 3 O 4 nanocompositewas synthesized as the gas sensing layer and Schottky contact was formed by Au electrodes. The Schottky contact functions as a “gate” which can trigger the avalanche breakdown effect in the TiO 2 -Sn 3 O 4 heterojunctions. By tuning the Schottky barrier height through the responsive variation of the surface chemisorbed gas and the bias on the device, NO 2 at a concentration from 5 to 50 ppm can be detected with an average response time of 8 s at room temperature. This nanostructured device is a promising candidate for application in high-sensitivity and high-speed NO 2 gas sensor. The methodology and working principle illustrated in this paper present a new sensing mechanism that can be readily and extensively applied to other gas sensing systems. • TiO 2 -Sn 3 O 4 heterostructure was designed and synthesized in order to detect NO 2 gas in room temperature. • Avalanche breakdown effect was used to obtain 900% responsivity when exposed to 50 ppm NO 2 at room temperature. • High sensitivity and excellent selectivity to NO 2 is obtained at room temperature.

A Scalable Model for Snapback Characteristics of Circuit-Level ESD Simulation

It is challenging to simulate the snapback behaviors under electrostatic discharge (ESD) stresses due to the limitation of simulation program with integrated circuit emphasis (SPICE) simulation tools. In this paper, a new model is proposed to investigate the avalanche breakdown effect using the voltage-controlled current source (VCCS), which greatly facilitates the calculation of the avalanche multiplication factor M and improves the convergence characteristics. In particular, this new method transfers the exponential relationship of M into the linear relationship of the VCCS gain. The versatility of the model is validated by its operations in various ESD protection circuits with MOS as the discharge device, while the scalability is demonstrated by its applications in varied device sizes.

Active control of terahertz waves based on p-Si hybrid PIT metasurface device under avalanche breakdown.

Active control of terahertz waves is a critical application for terahertz devices. Silicon is widely used in large-scale integrated circuit and optoelectronic devices, and also shows great potential in the terahertz field. In this paper, a p-Si hybrid metasurface device is proposed and its terahertz characteristics under avalanche breakdown effect is investigated. In the study, a plasmon-induced transparency (PIT) effect caused by the near-field coupling of the bright mode and the dark mode is observed in the transmission spectrum. Due to avalanche breakdown effect, the resonance of the PIT metamaterial disappears as the current increased. Carriers existed in the interface between the metasurface and substrate result to a dipole resonance suppression. When the current continues increasing, the maximal modulation depth can reach up to 99.9%, caused by the avalanche effect of p-Si. Experimental results demonstrate that the avalanche breakdown p-Si can achieve a performance modulation depth, bringing much more possibilities for terahertz devices.

Investigation of the effect of doping the GaN buffer layer with carbon on the avalanche breakdown effect of normally open HEMT AlGaN/AlN/GaN transistors

The influence of the GaN buffer layer doped with carbon on the avalanche breakdown effect of normally open HEMT AlGaN / AlN / GaN transistors was studied. The avalanche breakdown was simulated in a structure where the gate length is LG = 0.3 mkm, the distance between the source and gate is LSG = 1.5 mkm, and the distance between the gate and drain is LGD = 2.2 mkm. For modeling, consider a layer doped with carbon, the thickness of which is 0.3 mkm, and the layer is located at a distance of 20 nm from the channel. The Simulation showed that with an increase in the concentration of carbon doping of the buffer, the breakdown voltage increases in the range UB = 225 – 360 (V). When the layer thickness changes to 0.4 mkm, the breakdown voltage increases in the range UB = 230 – 446 (V). For a structure where the gate length is LG = 0.8 mkm, the distance between the source and the gate is LSG = 1.0 mkm, the distance between the gate and drain is LGD = 3.0 mkm, the breakdown voltage increases in the range UB = 300 – 622 (V).

Hugely Enhanced Output Power of Direct‐Current Triboelectric Nanogenerators by Using Electrostatic Breakdown Effect

AbstractElectrostatic breakdown is a common but generally negative physical phenomenon. Here, efficient conversion of mechanical energy to electric power is achieved by enhanced direct‐current triboelectric nanogenerator (DC‐TENG) based on contact electrification and electrostatic breakdown. By verifying the high temperature can not only improve the triboelectric charge density but also enhance electrostatic breakdown of air dielectric due to thermionic emission of electrons and avalanche breakdown effect. Meanwhile an appropriate low atmosphere pressure is another favorable factor to air breakdown in DC‐TENG. As a result, its output power density is improved by three orders of magnitude at 473 K and 300 Pa compared to that at 298 K and standard atmosphere pressure. These findings not only provide a new paradigm to design high‐performance TENG, but realize efficiently harvesting mechanical energy and thermal energy in one device by coupling the two kinds of physical effects.

In-situ detection of local avalanche breakdown and large magnetoresistance in Ag/SiO2/p-Si:B/SiO2/Ag device

Local avalanche breakdown in an Ag/SiO2/p-Si:B/SiO2/Ag device was successfully detected by an in-situ detection circuit, which was composed of a p-Si:B substrate, two p-Si:B/SiO2/Ag metal-oxide-semiconductor (MOS) structures formed on it, and a voltmeter. In our device, we observed a series of discharge peaks in the voltage-current curves which were corresponding to the generation of local plasmas in avalanche regimes. The generation of local plasmas led to a sudden increase in carriers concentration in the substrate which resulted in sudden voltage drops across the detection circuit, and then the MOS structures started to discharge which led to discharge peaks observed in V-I characteristics. More interesting, we found that the shape and amplitude of discharge peaks strongly depended on the setting of current steps of current source, owing to the discharging progresses. The avalanche breakdown based magnetoresistance (MR) effects were also studied. The value of MR in avalanche breakdown regime was about 40% which was two orders of magnitude higher than the MR value in other regimes. This work provides a simple and convenient method to explore the local avalanche breakdown effect and pave a way to acquire the MR effects based on avalanche breakdown.

SiGe HBT Large-Signal Table-Based Model With the Avalanche Breakdown Effect Considered

In this paper, a table-based large-signal model for silicon germanium heterojunction bipolar transistors with the introduction of a breakdown network is presented to describe the avalanche breakdown effect of the base-collector junction on direct current and RF characteristics completely. Input oscillation and output inductive behaviors in the breakdown regime are found to be due to impact ionization induced holes and electrons, respectively. The avalanche breakdown effect and early effect modeled by the breakdown network and output resistance, respectively, can be distinguished in the presented model. In addition, a good agreement between the extracted total input and output resistances at RF and dc is obtained. The validity of this presented large-signal table-based model with multibias intrinsic parameters has been verified through the measured output spectrum and waveform.

Avalanche breakdown effects on AlGaAs/GaAs HBT performance

The performance of heterojunction bipolar transistors operating in the avalanche breakdown regime has been evaluated. The analysis shows that AlGaAs/GaAs HBT under avalanche breakdown has higher collector-base junction capacitance, lower Early voltage, higher device noise, lower power efficiency, lower cut-off frequency, reduced device switching speed, and degraded maximum frequency of oscillation.

One-dimensional numerical simulation of complementary power Schottky structures

A short review of the history and modelling of Schottky structures is given. A one-dimensional numerical model including tunnelling and avalanche breakdown effects for the Schottky structures is described. Simulation results on complementary power Schottky structures for the three different barrier heights (data for Cr, W, Al) are carried out for DC and transient response.