Differential surface photovoltage spectroscopy characterization of a 1.3 μm InGaAlAs/InP vertical-cavity surface-emitting laser structure

Abstract

We have investigated a 1.3 m InGaAlAs/InP vertical-cavity surface-emitting laser ͑VCSEL͒ structure using angle-and temperature-dependent wavelength-modulated differential surface photovoltage spectroscopy ͑DSPS͒. The DSPS measurements as functions of incident angle and temperature have been carried out in the ranges 0°рр60°and 300 KрTр420 K, respectively. Angle-dependent reflectance ͑R͒ and surface photovoltage spectroscopy ͑SPS͒ measurements have also been performed to illustrate the superior features of the DSPS technique. The differential surface photovoltage ͑DSPV͒ and SPV spectra exhibit both the fundamental conduction to heavy-hole excitonic transition of quantum well and cavity mode ͑CM͒ plus a rich interference pattern related to the mirror stacks, whereas in the R spectra only the CM and interference features are clearly visible. The energies of the excitonic transition and CM are accurately determined from the DSPV spectra. By changing the angle of incidence in the DSPS measurements the energy positions of the CM and distributed Bragg reflector features show a blueshift while the excitonic transition remains unchanged. At a fixed incident angle, the energy positions of the excitonic feature and CM show a different rate of redshift with increasing temperature, with the latter at a much slower pace. The results demonstrate considerable potential of DSPS for the nondestructive characterization of the VCSEL structures.

Differential surface photovoltage spectroscopy of δ‐doped GaAs/AlAs multiple quantum wells below and close to Mott transition

“…However, as was shown recently [19,20], modulation spectroscopy techniques, such as photo-and electroreflectance [20,21] or differential surface photovoltage (DSPV) [19,22], are very suitable for examining the electronic structure and doping effects on excitonic resonances in QWs with high spectral sensitivity even at room temperature. Our earlier DSPV studies of Be δ-doped GaAs/AlAs multiple QWs (MQWs) [19] demonstrated that doping effects are not critical for the observation of excitonic transitions at acceptor densities up to 2.5 × 10 12 cm -2 .…”

“…A light from a 100 W tungsten halogen lamp was passed through a grating monochromator SPM-2 and focused onto the sample. In DSPV spectra measurements, we have used a wavelength-modulation technique [22]. The wavelength λ of the incident probe light was modulated by vibrating at 87 Hz a fused-silica plate located near the exit slit of the monochromator.…”

Room temperature spectroscopic characterization of mid-infrared GaInSb quantum-well laser structures

“…SPS spectra can be analysed by several methods [7,[11][12][13]. Here, following [13], we fit in the QW region with an appropriate sum of excitonic Gaussian peaks to obtain the QW transition energies.…”