The Rate of Radiative Recombination in the Nitride Semiconductors and Alloys

Abstract

The radiative recombination rates have been calculated for the first time in the wide band gap wurtzite semiconductors GaN, InN and AlN and their solid solutions Ga x Al 1-x N and In x Al 1-x N on the base of existing data on the energy band structure and optical absorption in these materials. We calculated the interband matrix elements for the direct optical transitions between the conductivity band and the valence one using the experimental photon energy dependence of the absorption coefficient near the band edge. In our calculations we assumed that the material parameters of the solid solutions (the interband matrix element, carrier effective masses and so on) could be obtained by a linear interpolation between their values in the alloy components. The temperature dependence of the energy gap was taken in the form proposed by Varshni. The calculations of the radiative recombination rates were performed in the wide range of temperature and alloy compositions.

High-quality p–n junctions with quaternary AlInGaN/InGaN quantum wells

“…[6][7][8] For our structure, the temperature dependence of the I -V slopes is proportional to 1/kT with practically no temperature dependence of the ideality factor, . The fact that in our samples is close to 2 indicates that the recombination current is a major mechanism of the current transport, in contrast to commonly observed tunneling mechanism for standard blue AlGaN/ InGaN LEDs and GaN p -n diodes.…”

“…The fact that in our samples is close to 2 indicates that the recombination current is a major mechanism of the current transport, in contrast to commonly observed tunneling mechanism for standard blue AlGaN/ InGaN LEDs and GaN p -n diodes. [6][7][8] The dependence of the saturation current on temperature for the AlInGaN LED was exponential with the activation energy of 1.22 eV. This value is about 200 meV smaller than that expected from the InGaN energy gap.…”

“…Much higher values of ideality factors Ϸ6-7 have been reported for GaN based p -n diodes and AlGaN/InGaN LEDs. [6][7][8] Such values are commonly attributed to the carrier tunneling rather than to the thermal diffusion and recombination. 6,7 In commercially available blue LEDs at low bias, the carrier tunneling in space charge region occurs either because of high doping of the active layer or due to the high density of localized states.…”

Modeling of a GaN Based Static Induction Transistor

“…-4 eV/K, and β=772 K, based on optical absorption measurements [15]. The electron (hole) low-field mobility as a function of the impurity concentration (N) and temperature T is given by [12]: …”

“…with C opt =3x10 -11 cm 3 /s, from absorption experimental data and calculated electron energy band dispersion [15].…”