Origin of the Broad Lifetime Distribution of Localized Excitons in InGaN/GaN Quantum Dots
نویسندگان
چکیده
We derive an energy-dependent decay-time distribution function from the multi-exponential decay of the ensemble photoluminescence (PL) of InxGa1-xN/GaN quantum dots (QDs), which agrees well with recently published singleQD time-resolved PL measurements. Using eight-band k·p modelling, we show that the built-in piezoand pyroelectric fields within the QDs cause a sensitive dependence of the radiative lifetimes on the exact QD geometry and composition. Moreover, the radiative lifetimes also depend heavily on the composition of the direct surrounding of the QDs. A broad lifetime distribution occurs even for moderate variations of the QD structure. Thus, for unscreened fields a multi-exponential decay of the ensemble PL is generally expected in this material system. (accepted at Physica Status Solidi (b). c ©2008 WILEY-VCH)
منابع مشابه
Correlating exciton localization with compositional fluctuations in InGaN/GaN quantum wells grown on GaN planar surfaces and facets of GaN triangular prisms
We have used spatially and temporally resolved cathodoluminescence CL to study the carrier recombination dynamics of InGaN quantum wells QWs grown on 0001 -oriented planar GaN and 11̄01 -oriented facets of GaN triangular prisms prepared by lateral epitaxial overgrowth in a metal-organic chemical vapor deposition system. The effects of In migration during growth on the resulting QW thickness and ...
متن کاملBroadband full-color monolithic InGaN light-emitting diodes by self-assembled InGaN quantum dots
We have presented broadband full-color monolithic InGaN light-emitting diodes (LEDs) by self-assembled InGaN quantum dots (QDs) using metal organic chemical vapor deposition (MOCVD). The electroluminescence spectra of the InGaN QDs LEDs are extremely broad span from 410 nm to 720 nm with a line-width of 164 nm, covering entire visible wavelength range. A color temperature of 3370 K and a color ...
متن کاملLuminescence studies on green emitting InGaN/GaN MQWs implanted with nitrogen
We studied the optical properties of metalorganic chemical vapour deposited (MOCVD) InGaN/GaN multiple quantum wells (MQW) subjected to nitrogen (N) implantation and post-growth annealing treatments. The optical characterization was carried out by means of temperature and excitation density-dependent steady state photoluminescence (PL) spectroscopy, supplemented by room temperature PL excitatio...
متن کاملExcitonic field screening and bleaching in InGaN/GaN multiple quantum wells
Photoinduced carrier dynamics in a sequence of InGaN/GaN multiple quantum wells (MQWs) are studied by employing steady state and ultrafast spectroscopy at room temperature. Time-resolved photoluminescence (PL) measured short carrier lifetimes of ,140 ps at room temperature. Steady state differential transmission was used to measure the in-well field screening due to the photoinjected carriers. ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008