Observation of minority-carrier traps in InGaN∕GaN multiple-quantum-well light-emitting diodes during deep-level transient spectroscopy measurements

Abstract

An unusual appearance of a peak in the deep-level transient spectroscopy (DLTS) data for minority-carrier traps from an InGaN∕GaN multiple-quantum-well (MQW) light-emitting diode, under a bias condition provided by a square pulse of varying height superimposed over the reverse-bias voltage, is newly observed and analyzed. The peak is attributed to hole traps, having the estimated activation energy of 0.7eV, in the last one (toward the p side) among the GaN barrier layers in the MQW structure. We have found that the ΔC∕Cr-versus temperature pattern from the DLTS measurement agrees well with the pattern predicted from the model of hole traps, i.e., the minority-carrier traps, in the MQW barrier layer, whose occupation probability is governed by the local hole quasi-Fermi level.

Stress-induced traps in multilayered structures

“…These defects act like traps and influence the electrical transport and phototransport in these structures. 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 For instance, the dark current is reduced as the carrier concentrations decrease due to the trapping. This effect is compensated in the case of the phototransport by the decrease of the recombination rate if either the electrons or holes are trapped.…”

“…23,24,25 Different methods were used to investigate these traps. The deep level transient spectroscopy (DLTS) method, 4,5,9,10,13,19,26 is the most used for the investigation of the deep traps. The method is based on the measurement of a transient junction capacitance and allows determining the energy of the trapping levels, as well as the concentration and capture cross-section of the trapping centers.…”

Polarization effect on electronic band structure of InGaN/GaN multi‐quantum wells

“…5 should be caused by a decrease of internal field. This band gap modification under reverse bias condition was proved by simulation [18]. On the other hand, the thermal activation energy of B1 state was not changed because the B1 state is located at deep level in bulk GaN.…”

Detection of Nonradiative Recombination Centers in GaPN (N:0.105%) by Below‐Gap Excitation Light

“…With increasing N concentration, the GaPN crystal forms NN i pairs in addition to the isoelectronic traps, and wavefunction of these overlaps each other to form an IB at a suitable energy for the application to IBSCs . In addition to forming the IB, N in GaP introduces N‐related defect levels which act as nonradiative recombination (NRR) centers . The actual efficiency of IBSCs is determined by the competition of cascade photo‐excitation rate via the IB, and other radiative and NRR rates with these NRR centers.…”