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Deals with a study that presented a model for the spectral response of gallium arsenide and Al[subx]Ga[sub1-x]As p-n and p-i-n solar cells based on a standard solution of the minority-carrier equations. Application of the quantum well solar cell; Capability of the model; Strengths and weaknesses of the model; Disadvantages from the use of intercell connection.

Presents information on a study which investigated the temperature dependence of the photoluminescence decay kinetics of a series of gallium arsenide (GaAs)/aluminum arsenide (AlAs) quantum-well structures where GaAs thickness was kept constants and AlAs was varied. Methodology of the study; Results and discussion; Conclusions.

We demonstrate a detection mechanism for 2-5 THz radiation using intersubband transitions between anticrossing electron levels in a GaAs/AlGaAs coupled-quantum-well photodiode. The THz radiation is detected as a modulation in the photocurrent generated by a visible laser. This modulation is caused by carrier heating effects due to absorption of energy by intersubband transitions. Since the frequency of the intersubband transitions varies with the electric-field strength, the device can function as a voltage-tunable THz detector. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Spontaneous emission spectra from GaAs quantum well lasers grown by molecular beam epitaxy show that the radiative recombination rate in (AlAs)(GaAs) superlattice barriers is greater than in alloy barriers of the same average composition (x=0.25) due to reduction in effective gap by superlattice effects. Measurements of emission spectra as functions of temperature show that these radiative processes account for a significant part of the temperature variation of the threshold current and we estimate that the nonradiative lifetime in the superlattice barriers is an order of magnitude longer than in alloy barriers grown under similar conditions. [ABSTRACT FROM AUTHOR]

Using quantum well laser devices with a window in the p-type contact, we have measured the relative change of spontaneous emission intensity at threshold with temperature for 58-Å-wide GaAs wells. Over the range 250–340 K the data are in good agreement with the linear relation obtained from a gain-current calculation which includes transition broadening. This linear behavior contrasts with the stronger temperature dependence of the total measured threshold current of the same devices which includes nonradiative barrier recombination processes. [ABSTRACT FROM AUTHOR]

We have used short-period all-binary (AlAs)(GaAs) superlattices with layers as thin as three monolayers to synthesize the barrier and cladding regions of GaAs quantum well lasers grown by molecular beam epitaxy. By studying the threshold current of single- and double-well devices as a function of cavity length and temperature, we conclude that the optical scattering losses are very low, that the gain-current characteristics are similar to alloy barrier devices, and that there is evidence for current leakage by recombination in the barriers. [ABSTRACT FROM AUTHOR]

Detection of continuous-wave terahertz (THz) radiation has been demonstrated in GaAs/AlGaAs coupled quantum well p-i-n photodiodes by intrasubband absorption. The sharp interwell tunneling resonances observed in the photocurrent are highly sensitive to temperature, and the carrier temperature increase caused by the absorption of THz radiation is found to affect the photocurrent in a qualitatively similar manner. We find that the effect results in detectivities of THz radiation around 1 mA/W for a photocurrent signal of 100 nA. We discuss the functionality of our device in the context of an ‘‘optical/THz mixer,’’ where the mixing occurs between the modulation frequencies of the applied THz and visible light fields. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]