4H-SiC Auger recombination coefficient under the high injection condition

Abstract

The on-resistance of bipolar devices depends on the carrier lifetime determined by Shockley-Read-Hall, surface, radiation and Auger recombination processes. Values for the Auger recombination coefficient have been previously reported, but the values were constant in each report. However, the Auger recombination coefficient should have dependence on the excited carrier concentration and presence of the traps. In this study, we observed excited carrier recombination in 4H-SiC under the high injection condition by time resolved free carrier absorption measurements. As a result, we found dependence on the excited carrier concentration of the Auger recombination coefficient and negligible effects of the traps on the coefficient.

Effect of dislocations on carrier recombination and photoelectrochemical activity in polished and unpolished TiO2 and SrTiO3 crystals

“…60,62 In addition, the Auger and bimolecular recombination which strongly depend on charge carrier concentration are negligible. 61,65 The temperature dependence of μ-PCD curves for undoped TiO 2 and SrTiO 3 single crystals excited by the 355 nm laser at an injected photon density of 5.7 × 10 14 cm -2 is shown in Fig. 2.…”

“…Yttrium aluminum garnet (YAG) lasers with wavelengths of 266 and 355 nm and pulse width of 1 ns were used as excitation light sources (FTSS 266-200 and FTSS 355-50, CryLas). 58,60,61,63,65 The spot size 63 of the two lasers was 0.13 cm -2 . The laser intensity was 0.06-0.6 mW for the 266 nm laser and 0.2-4.0 mW for the 355 nm laser.…”

Analysis of defects dominating carrier recombination in CeO2 single crystal for photocatalytic applications

“…For the PL and TR-PL measurements, we used a multichannel spectrometer and a photomultiplier as the detector, respectively. A long-pass filter (w/ o 565 BPF) with a cut-off wavelength of 355 nm was placed in front of the multichannel spectrometer or photomultiplier [24,[26][27][28][29]. To measure the TR-PL separately, a 565 nm (2.19 eV) band-pass filter (w/ 565 BPF) with a center wavelength of 565 nm and a peak transmission width of 133 nm (498.5-631.5 nm, 1.96-2.49 eV) was positioned between the 355 nm long-pass filer and the photomultiplier.…”

Carrier recombination in highly Al doped 4H-SiC: dependence on the injection conditions

“…9,10) However, carrier recombination mechanisms in p-type 4H-SiC are not fully understood, 7,[11][12][13][14][15][16][17][18][19][20][21] compared with those in n-type 4H-SiC. 9,[22][23][24][25][26][27][28][29][30][31][32][33][34][35] Aluminum (Al) is the common acceptor impurity in 4H-SiC, and recombination mechanisms in highly Al doped ptype 4H-SiC epitaxial layers are still unclear. Hydrogen passivation effects and Al doping concentration dependence on the carrier lifetime have been reported.…”