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.

A Large Magnetoresistance Effect in p-n Junction Devices by the Space-Charge Effect

Abstract: The fi nding of an extremely large magnetoresistance effect on silicon based p–n junction with vertical geometry over a wide range of temperatures and magnetic fi elds is reported. A 2500% magnetoresistance ratio of the Si p–n junction is observed at room temperature with a magnetic fi eld of 5 T and the applied bias voltage of only 6 V, while a magnetoresistance ratio of 25 000% is achieved at 100 K. The current-voltage ( I–V ) behaviors under various external magnetic fi elds obey an exponential relationship, and the magnetoresistance effect is signifi cantly enhanced by both contributions of the electric fi eld inhomogeneity and carrier concentrations variation. Theoretical analysis using classical p–n junction transport equation is adapted to describe the I–V curves of the p–n junction at different magnetic fi elds and reveals that the large magnetoresistance effect origins from a change of space-charge region in the p–n junction induced by external magnetic fi eld. The results indicate that the conventional p–n junction is proposed to be used as a multifunctional material based on the interplay between electronic and magnetic response, which is signifi cant for future magneto-electronics in the semiconductor industry.

Analysis of the temperature dependence of the forward voltage characteristics of GaInN light-emitting diodes

Abstract: The forward voltage characteristics of GaInN light-emitting diodes are studied in the temperature range of 80 K to 450 K. The forward-voltage-vs.-temperature curve has a “two-slope” characteristic with a slope of dVf/dT = −1.7 mV/K and −8.0 mV/K at room temperature and cryogenic temperatures, respectively. To investigate the two-slope characteristic, we perform transmission-line-model measurements on p-type GaN and show that both p-type contact and sheet resistance decrease drastically with increasing temperature. We conclude that dVf/dT in the high-slope region is limited by p-type sheet and contact resistance, and in the low-slope region by the GaN pn junction properties.

Carrier dynamics in nitride-based light-emitting p-n junction diodes with two active regions emitting at different wavelengths

Abstract: The carrier transport and recombination dynamics of monolithic InGaN/GaN light-emitting p-n junction structures with two active regions are investigated. Room-temperature and low-temperature photoluminescence and room-temperature electroluminescence measurements show two emission bands originating from the two active regions. In electroluminescence, the intensity ratio of the two emission bands is independent of injection current. In contrast, the intensity ratio depends strongly on the excitation intensity in photoluminescence measurements. The dependency of the emission on excitation is discussed and attributed to carrier transport between the two active regions and to the different carrier injection dynamics in photoluminescence and electroluminescence. The luminous efficacy of a Gaussian dichromatic white-light source is calculated assuming a line broadening ranging from 2kT to 10kT. Luminous efficacies ranging from 380 to 440 lm/W are obtained for broadened dichromatic sources.

Interface investigation of planar hybrid n-Si/PEDOT:PSS solar cells with open circuit voltages up to 645 mV and efficiencies of 12.6 %

Abstract: We have studied interface formation properties of hybrid n-Si/PEDOT:PSS solar cells on planar substrates by varying the silicon substrate doping concentration (N D). Final power conversion efficiencies (PCE) of 12.6 % and open circuit voltages (V oc) comparable to conventional diffused emitter pn junction solar cells have been achieved. It was observed, that an increase of N D leads to an increase of V oc with a maximal value of 645 mV, which is, to our knowledge, the highest reported value for n-Si/PEDOT:PSS interfaces. The dependence of the solar cell characteristics on N D is analyzed and similarities to minority charge carrier drift-diffusion limited solar cells are presented. The results point out the potential of hybrid n-Si/PEDOT:PSS interfaces to fabricate high performance opto-electronic devices with cost-effective fabrication technologies.

Interplay of built-in potential and piezoelectric field on carrier recombination in green light emitting InGaN quantum wells

Abstract: The authors measure the interplay of piezoelectric field and built-in potential on carrier recombination and quantum confined Stark effect in green light emitting InGaN quantum wells by modulating the external bias voltage of the pn junction. Time-resolved electroluminescence shows a temporal separation of carrier injection into the active region and radiative recombination within the InGaN quantum wells. During the time when the bias voltage is off, the piezoelectric field is partially compensated by the built-in potential of the pn junction, resulting in an increased radiative recombination rate.