Evidence of nanoscale Anderson localization induced by intrinsic compositional disorder in InGaN/GaN quantum wells by scanning tunneling luminescence spectroscopy

Abstract

We present direct experimental evidences of Anderson localization induced by the intrinsic alloy compositional disorder of InGaN/GaN quantum wells. Our approach relies on the measurement of the luminescence spectrum under local injection of electrons from a scanning tunneling microscope tip into a near-surface single quantum well. Fluctuations in the emission line shape are observed on a few-nanometer scale. Narrow emission peaks characteristic of single localized states are resolved. Calculations in the framework of the localization landscape theory provide the effective confining potential map stemming from composition fluctuations. This theory explains well the observed nanometer scale carrier localization and the energies of these Anderson-type localized states. The energy spreading of the emission from localized states is consistent with the usually observed very broad photo- or electro-luminescence spectra of InGaN/GaN quantum well structures.

5 pages, 5 figures + supplemental material (1 page, 1 figure)

References in corpus (7)

• Unraveling the "Green Gap" problem: The role of random alloy fluctuations in InGaN/GaN light emitting diodes
• Carrier localization mechanisms in InGaN/GaN quantum wells
• Localization landscape theory of disorder in semiconductors. III. Application to carrier transport and recombination in light emitting diodes
• Effective confining potential of quantum states in disordered media
• Localization landscape theory of disorder in semiconductors II: Urbach tails of disordered quantum well layers
• Atomistic analysis of the impact of alloy and well-width fluctuations on the electronic and optical properties of InGaN/GaN quantum wells
• Localization landscape theory of disorder in semiconductors I: Theory and modeling

Cited by in corpus (9)

• Three-dimensional modeling of minority-carrier lateral diffusion length including random alloy fluctuations in (In,Ga)N and (Al,Ga)N single quantum wells
• Evidence of localization effect on photoelectron transport induced by alloy disorder in nitride semiconductor compounds
• Direct Observation of Ultrafast Singlet Exciton Fission in Three Dimensions
• Long coherent dynamics of localized excitons in (In,Ga)N/GaN quantum wells
• Probing alloy formation using different excitonic species: The particular case of InGaN
• Localized Energy States Induced by Atomic-Level Interfacial Broadening in Heterostructures
• Probing local emission properties in InGaN/GaN quantum wells by scanning tunneling luminescence microscopy
• Plasma Profiling Time-of-Flight Mass Spectrometry for Fast Elemental Analysis of Semiconductor Structures with Depth Resolution in the Nanometer Range
• Increased light-emission efficiency in disordered InGaN through the correlated reduction of recombination rates