Excitonic transitions in Si delta-doped GaAs studied with wavelength modulated lateral photoconductivity

The New Photothermal Wavelength Modulated Photocurrent (PTWMPC) technique was recently used and demonstrated as a simple method for studying the excitonic transitions under the bandgap in Si delta-doped GaAs. The spectroscopic aspects of PTWMPC have been theoretically and experimentally studied. The PTWMPC phenomena and the nature of registered features are explored in details. The PC spectrum line shape, the full width at half-maximum intensity dependence, the chopping frequency and the excitonic peaks position intensity dependence are discussed. The PTWMPC can be proposed as a simple external resonator optoelectronic technique for laser diode frequency stabilization and the Si delta-doped GaAs cell is useful as a device with sharp reference frequency absorption peaks for metrological purposes. (C) 2000 Elsevier Science BN. All rights reserved.