Carrier recombination dynamics in Si doped InN thin films

Abstract

Time-integrated and time-resolved photoluminescence (PL) of InN thin films of different background carrier concentrations are investigated. The PL formation mechanism is attributed to the “free-to-bound” transition by analyzing the time-integrated PL spectra at different pump fluences. The dependence of the PL decay time with emission energy is investigated using a theoretical model which speculates upon the carrier localization in InN thin films. The radiative lifetime, mobility edge, and carrier localization energy are obtained from the dependence of the PL decay time on emission energy and are studied at different background carrier concentrations. The effect of intervalley scattering between the Γ1 and Γ3 valley on the radiative lifetime, mobility edge, and carrier localization energy is discussed. The longer radiative lifetime and smaller values of the mobility edge and localization energy for 3.06 eV excitation are observed than that for the 1.53 eV excitation due to the intervalley scattering process.

Towards the indium nitride laser: obtaining infrared stimulated emission from planar monocrystalline InN structures

“…The detailed studies of this series of structures have been previously carried out by several scientific groups, including studies of the temperature and power dependencies of the photoluminescence spectra under CW optical pumping 2 , 21 , 25 and time-resolved transmission measurements 26 , 27 . We should note that to our knowledge, no attempts were made in previous studies to obtain stimulated emission in InN structures similar to those studied in this work, including PL studies under pulsed optical pumping 28 , 29 . The samples obtained in IPM RAS and at Cornell University are marked in the text by the prefixes “IPM” and “GS”, respectively.…”

Observation of weak carrier localization in green emitting InGaN/GaN multi-quantum well structure

“…Therefore, the In concentration can be obtained from the peak energy of PL emission at room temperature using the relation, 38 E g, InN þ (1 À x) E g, GaN À bx (1 À x); where b is the band gap bowing parameter, and E g (x), E g, InN and E g, GaN are the band-gap energy of the In x Ga 1 À x N, InN and GaN, respectively. Considering the revised value of E g, InN as 0.65 eV, 39 E g, GaN as 3.4 eV, 1 and b as 1.21 eV, 38 the In concentration in the InGaN QW layer of our InGaN/GaN MQW sample is estimated to be about 30%.…”

Injection-Activated Defect-Governed Recombination Rate in InN

“…Investigation of photoluminescence (PL) properties raised different origins of radiative emission, ranging from defect-related to interband transitions with a possible impact of carrier localization. [1][2][3][4][5][6] Nevertheless, still controversial PL emission mechanisms revealed the decrease of the radiative lifetime with increase of n 0 what implied the enhancement of nonradiative recombination process to increasing concentration of defects. 1,3) Therefore understanding of nonradiative recombination mechanisms which dominate in InN can be considered of upmost importance.…”

“…[1][2][3][4][5][6] Nevertheless, still controversial PL emission mechanisms revealed the decrease of the radiative lifetime with increase of n 0 what implied the enhancement of nonradiative recombination process to increasing concentration of defects. 1,3) Therefore understanding of nonradiative recombination mechanisms which dominate in InN can be considered of upmost importance. The latter have been extensively investigated in the last decade and revealed carrier lifetimes ranging from $50 ps to 1.3 ns which varied inversely with n 0 (from 4 Â 10 17 to 10 19 cm À3 ) suggesting that the donor-like defects are responsible for a formation of recombination centers.…”