Exciton luminescence of single-crystal GaN

Book · Fri Nov 01 04:00:00 EST 1996

OSTI ID:395013

Muellhaeuser, J R; Brandt, O; Yang, H; Ploog, K H ^[1]

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1. Paul-Drude-Inst. fuer Festkoerperelektronik, Berlin (Germany)

Detailed photoluminescence (PL) studies of high-quality MBE-grown single-crystal cubic and hexagonal GaN are presented. The authors identify free and bound exciton recombination. By means of a line-shape analysis, they quantitatively analyze the spectra, which were taken as a function of temperature (T = 4--300 K) and excitation density (P{sub ex} = 0.3--200 W/cm{sup 2}). The authors show the dominant recombination channel at 300 K to be free-excitonic in nature with an internal small-signal quantum efficiency of 6 {times} 10{sup {minus}3} for both cubic and hexagonal material. Based on a three-level model, activation energies for exciton dissociation are evaluated. Radiative ({tau}{sub rad} {approx} 2 ns) and nonradiative lifetimes ({tau}{sub e} {approx} 1 {micro}s, {tau}{sub h} {approx} 20 ps) are determined, where in the latter case, electron and hole trapping are considered separately. Furthermore, the authors show that the dominant nonradiative recombination center, being a hole trap, saturates at P{sub ex} {ge} 20 W/cm{sup 2}.

• OSTI ID: 395013
• Report Number(s): CONF-951155--; ISBN 1-55899-298-7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ELECTRON DIFFRACTION
ELECTRONIC EQUIPMENT
EXCITATION
EXPERIMENTAL DATA
GALLIUM ARSENIDES
GALLIUM NITRIDES
LASER RADIATION
PHOTOLUMINESCENCE
QUANTUM EFFICIENCY
RADIATIVE DECAY
RECOMBINATION
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SUBSTRATES
TEMPERATURE DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION