Photocurrent measurements of InGaN/GaN quantum wells under hydrostatic and uniaxial pressure

Abstract

Light emitting diode structures with InGaN quantum wells have been studied as a function of hydrostatic and uniaxial pressure (along the c-axis) under different values of reverse voltage. Photocurrent measurements (with light parallel to the epitaxial layers) allow determining energies in transverse electric (TE) and transverse magnetic (TM) polarizations, which we attribute to transitions from the heavy-hole (HH) and crystal-field split (CH) band to the conduction band. The comparison of theory and experiment suggests that the electric fields are about 25% lower than the calculated values. The transitions in TE polarization agree with the theoretical predictions, while those in TM polarization do not. In particular, the splittings between HH and CH bands are lower than the theoretical predictions.

The infuence of compressive lattice deformations on the zone-center energy band properties of zincblende GaN and InN. Hybrid density functional results

“…On the other hand, it is well known that uniaxial strain plays a significant role in the case of WZ nitride nanosystems. This has been recently verified through experimental investigation of InGaN/GaN quantum wells in which uniaxial and hydrostatic deformations wer induced [24,25]. Throughout the years, theoretical research on strain effects in both ZB and WZ nitrides have been carried out with the use of microscopic approaches such as density-functional theory (DFT) and empirical pseudopotentials [26][27][28][29][30][31].…”

Theoretical and Experimental Studies on Material Gain for Wide Polar InGaN Quantum Well‐Mechanism Leading to Electric Field Screening and Lasing

“…Quite often, staggered QWs have been considered. [18][19][20][21][22][23][24] In this case, it is possible to obtain a better ground-state electron-hole overlap with appropriate polarization engineering, but the total thickness of the step-like barriers and QW is still below 5 nm, [18][19][20][21] which is very far from the width typical of non-polar QWs in III-V semiconductors, that is, 8-15 nm. [25][26][27][28] In contrast, lasing for wide InGaN QWs has been demonstrated experimentally.…”

Фотореверсивный ток в светодиодных гетероструктурах на основе InGaN/GaN c разным количеством квантовых ям

“…Этот метод связан с поглощением монохроматического излучения при фотовозбуждении связанных электронов из валентной зоны в зону проводимости [3]. Ранее такие исследования проводились для структур на основе слоев InGaN/GaN с разной концентрацией индия в квантовых ямах активной области [4], при гидростатическом давлении [5], с разной концентрацией Mg в барьерах [6]. В указанных работах авторы изменяли состав, количество слоев, а также концентрацию примесей в активной области с целью поиска оптимальной зонной структуры готового устройства.…”