Optical studies of carrier dynamics and non-equilibrium optical phonons in nitri

2020-03-14 04:44:31

optical nitride carrier phonons semiconductors

责任者: Tsen, K.T.;Liang, W.;Ferry, D.K.;Hai Lu;Schaff, W.J.;Ozgur, U.;Fu, Y.;Moon, Y.T.;Yun, F.;Morkoc, H.;Everitt, H.O. 单位: 来源出处: Superlattices and Microstructures(Superlattices Microstruct. (UK)),2005/08/,38(2):77-114 摘要: Ultrafast optical probes, photoluminescence spectroscopy, and Raman spectroscopy have been applied to investigate carrier dynamics in nitride-based binary and ternary, and dilute nitride semiconductors. Carrier dynamics in the form of radiative and non-radiative lifetimes in GaN grown on pseudo-in situ TiN and in situ SiN nanonetworks by organometallic vapor phase epitaxy have been investigated and compared with those for freestanding GaN templates which constitute the benchmark values due to the high quality. Room temperature carrier lifetimes as long as 1.86 ns could be achieved with the use of TiN network templates. Time-resolved Raman spectroscopy has been employed to investigate the carrier dynamics, carrier transport and non-equilibrium optical phonons in In-containing nitride-based semiconductors. (1) It has been found that the energy loss rate in InxGa1-xAs1-yNy is about 64meV/ps suggesting that hot electrons lose their energy primarily to the GaAs-like LO phonons in this dilute nitride semiconductor. (2) Both the non-equilibrium electron distribution and the electron drift velocity in InGaN and InN have been measured. These experimental results are compared with ensemble Monte Carlo calculations and good agreement is found. (3) Our experimental results support the small bandgap value for InN (approximately 0.8eV) and are inconsistent with the 0.8eV luminescence emission being due to deep level radiative emission. [All rights reserved Elsevier] 关键词: carrier lifetime;deep levels;gallium arsenide;gallium compounds;high-speed optical techniques;hot carriers;III-V semiconductors;indium compounds;losses;MOCVD coatings;phonons;photoluminescence;radiative lifetimes;Raman spectra;time resolved spectra;wide band gap semiconductors;carrier dynamics;nonequilibrium optical phonons;nitride-based wide bandgap semiconductors;ultrafast optical probes;photoluminescence spectroscopy;time-resolved Raman spectroscopy;nitride-based binary semiconductors;nitride-based ternary semiconductors;dilute nitride semiconductors;radiative lifetime;nonradiative lifetime;pseudo-in situ TiN nanonetwork;in situ SiN nanonetwork;organometallic vapor phase epitaxy;freestanding GaN templates;room temperature carrier lifetimes;carrier transport;energy loss rate;hot electrons;GaAs-like LO phonons;nonequilibrium electron distribution;electron drift velocity;ensemble Monte Carlo calculation;bandgap value;luminescence emission;deep level radiative emission;293 to 298 K;InxGa1-xAs1-yNy;InN;SiN;GaN