Room Temperature Near-Infrared Photoresponse Based on Interband Transitions in $\hbox{In}_{0.35}\hbox{Ga}_{0.65}\hbox{As}$ Multiple Quantum Dot Photodetector

Abstract

Near-infrared photoresponse is observed in the temperature range of 77-300 K for a photodetector fabricated from undoped In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.35</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.65</sub> As/GaAs multiple quantum dots grown in a molecular beam epitaxy system. The detectivity is estimated to be on the order of 3.70 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> and 2.70 X 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> cm .radicHz/W at 77 and 300 K, respectively. The reduction of the detectivity is attributed to the increase of the dark current as the temperature is increased. The photoresponse is explained in terms of several interband transitions. These transitions are found to be in good agreement with the self-consistent theoretical calculations.