p–n junction

About: p–n junction is a research topic. Over the lifetime, 7701 publications have been published within this topic receiving 108890 citations. The topic is also known as: p-n junction.

Optoelectronic semiconductor diodes and devices comprising same

Abstract: An optoelectronic semiconductor diode is made from a layer of many small individual particles (2) containing doping junctions (10) positioned between two contact surfaces (6, 8) mechanically supported by substrates (4). In the preferred embodiment, the particles are formed of a semiconductor, such as indium gallium nitride, as the active region. The particles are of a size on the order of 10 to 100 microns and are formed by reacting metallic gallium and indium with ammonia, or by a similar method. Electrical contacts are made to the particles (2) by conductive films (6, 8) that have been deposited on the inner surfaces of the substrates (4). These contacts can be either reflective or transparent. The particles (2) each contain a p-n or similar junction (10), created either by diffusing in dopants or by selectively activating dopants that are already present. When a forward bias is applied to a so formed LED, minority carriers spill over the junction (10) and recombine with majority carriers, thus producing light. Powder LEDs according to the present invention can in principle be manufactured to operate on any wavelength within the visible spectrum.

Complex opto-isolator with improved stand-off voltage stability

Abstract: Improved resistance to electrical instability of opto-isolators subjected to large stand-off voltages is obtained by coating the semiconductor light sensing element with a high resistivity layer of amorphous silicon while leaving most of the surface PN junction perimeter and nearby regions free of metal. The amorphous silicon prevents mobile ions in the encapsulation, which are driven to the detector surface by the stand-off voltage, from inverting or modulating the conductivity of the detector surface and causing instability. The amorphous silicon also makes it possible to leave most of the light sensitive PN junctions and nearby regions free of metal, thereby simplifying design of complex IC detector chips and increasing sensitivity.

"Paradoxes" of carrier lifetime measurements in high-voltage SiC diodes

Abstract: For Silicon Carbide (SiC) high-voltage rectifier diodes, contradictions appear when the most important parameter of the diodes, the minority carrier lifetime, is measured by different techniques. A qualitative analysis and a computer simulation have been carried out to clarify the origin of these contradictions. For 4H-SiC p/sup +/n diodes with 6 kV blocking capability, data on residual voltage drop at high current densities, switch-on time, reverse current recovery, and post-injection voltage decay are analyzed. It is shown that the whole set of experimental data can be explained by the existence of a thin (l/spl sim/0.1 /spl mu/m) layer near the metallurgical boundary of the p/sup +/n junction with very small carrier lifetime /spl tau//sub l/ that is essentially smaller than the carrier lifetime /spl tau/ across the remaining part of the 50-/spl mu/m n-base. It is emphasized that the existence of such a layer allows, under certain conditions, the combination of a relatively low residual forward voltage drop and very fast reverse recovery. Approaches to minority carrier lifetime measurements are discussed.

Noise due to generation and recombination of carriers in p-n junction transition regions

Abstract: The theory for the current noise associated with carrier generation and recombination in a p-n junction transition region is presented. The noise model is derived directly from the SRH defect center model. In a reverse biased junction the noise from this mechanism varies from two-thirds to full shot noise, depending upon frequency, and in a forward biased junction the noise ranges from three-fourths to full shot noise, depending upon injection level. These results approximately agree with published experimental results, but the agreement is not conclusive, especially in forward biased junctions. The theory shows that the noise associated with transition region generation-recombination current is not particularly significant in bipolar transistors.