Quantum-Confined Stark Effect due to Piezoelectric Fields in GaInN Strained Quantum Wells

Abstract

We have studied the influence of piezoelectric fields on luminescence properties of GaInN strained quantum wells. Our calculation suggests that an electric field of 1.08 MV/cm is induced by the piezoelectric effect in strained Ga0.87In0.13N grown on GaN. The photoluminescence peak energy of the Ga0.87In0.13N strained quantum wells showed blue shift with increasing excitation intensity. Moreover, the well-width dependence of its luminescence peak energy was well explained when the piezoelectric fields were taken into account. These results clearly showed that the piezoelectric field induced the quantum-confined Stark effect.

Room temperature PL efficiency of InGaN/GaN quantum well structures with prelayers as a function of number of quantum wells

“…4). This is attributed to the increasing total field across a QW, leading to an enhanced quantum confined Stark effect (QCSE) [18], consistent PL decay transients were obtained at T = 10 K, at which temperature the decay is assumed to be solely radiative, at the QW peak energy for each sample using an excitation energy density per pulse of 9.90 μJ cm -2 and are shown for samples 1QW, 3QW, and 15QW in Fig. 5.…”

Progress in the optical studies of single InGaN/GaN quantum dots

“…This field arises from both spontaneous polarization and piezoelectricity, with piezoelectric constants of nitride semiconductors being up to ten times larger than those of conventional III-V and II-VI compounds [6]. This field is believed to have a strong impact on device functionality as it causes a luminescence wavelength shift [7,8] and a reduction of the oscillator strength [9,10]. Furthermore, it has been predicted that this property, together with the high electron and hole effective masses, would make GaNbased QDs interesting candidates for quantum information processing (QIP) [11,12].…”

Excitonic field screening and bleaching in InGaN/GaN multiple quantum wells

“…The success in developing light sources has included the commercialization of blue, green and amber light emitting diodes and violet laser diodes. In spite of these developments, the emission mechanisms of these materials are still not fully understood due to the complex material physics, including indium clustering resulting from phase separation [3,4] in InGaN alloys and strain-induced piezoelectricity [5] due to the large lattice constant mismatch between GaN and InGaN. The incorporated InGaN/GaN quantum wells (QWs) within these structures and the resulting emission, absorption, and associated field and localization effects significantly complicate the understanding of these materials.…”

“…To date, several groups have discussed the blue shift of the photoluminescence (PL) peak energy in InGaN/GaN heterostructures with increasing carrier injection. The observed carrier dynamics has been described using models that attribute the behavior to either the reduction of the quantum-confined Stark effect due to in-well field screening [5,9,10] band-filling of the energy band tail states [11,12] or both [13,14]. The main reason that these studies have not been able to directly elucidate these complicated dynamics is because traditional time integrated PL and time-resolved PL measurements allow only the radiative recombination dynamics to be directly characterized.…”