Excitonic and electron-hole contributions to the spontaneous recombination rate of injected charge carriers in GaAs-GaAlAs multiple quantum well lasers at room temperature

The spontaneous recombination rate at room temperature of GaAs‐GaAlAs multiple quantum well lasers is investigated at carrier densities of 2×1017–1.7×1018 cm−3 using the small‐signal electroluminescence technique. A monomolecular, partly excitonic, and a bimolecular term contribute to the recombination rate R(n)=An+Bn2, where A and B are 2.08×108 s−1 and 1.5×10−10 cm3 s−1, respectively, for a well width Lz =7.5 mm. The radiative and nonradiative contributions to the linear recombination term, A=1/τr+1/τnr, are determined as τr =8 ns and τnr =12 ns from the dependence of the spontaneously emitted light power on the injection current density. In addition the carrier density dependence of the internal quantum efficiency is reported and ηi is found to be close to unity. The results demonstrate that even at fairly high excitation levels, excitonic enhancement of radiative recombination in high quality multiple quantum well structures is an important factor.

[1]  Thomas L. Paoli,et al.  Saturation of the junction voltage in stripe‐geometry (AlGa)As double‐heterostructure junction lasers , 1976 .

[2]  O. G. Folberth,et al.  Solid State Devices 1985 , 1986 .

[3]  D. Bimberg,et al.  Evidence for excitonic decay of excess charge carriers in high quality GaAs quantum wells at room temperature , 1986 .

[4]  Dieter Bimberg,et al.  Injection, intersubband relaxation and recombination in GaAs multiple quantum wells , 1985 .

[5]  Kohroh Kobayashi,et al.  A GaAs-AlxGa1-xAs Double Heterostructure Planar Stripe Laser , 1973 .

[6]  W. Tsang,et al.  cw narrow beam (AlGa)As multiquantum‐well heterostructure lasers grown by molecular beam epitaxy , 1981 .

[7]  Amnon Yariv,et al.  QUANTUM WELL LASERS , 1985 .

[8]  Won-Tien Tsang,et al.  The effects of lateral current spreading, carrier out‐diffusion, and optical mode losses on the threshold current density of GaAs‐AlχGa1−χAs stripe‐geometry DH lasers , 1978 .

[9]  M. G. Roe,et al.  Picosecond recombination of charged carriers in GaAs , 1986 .

[10]  Stephen D. Hersee,et al.  Some characteristics of the GaAs/GaAlAs graded‐index separate‐confinement heterostructure quantum well laser structure , 1984 .

[11]  D. Bimberg,et al.  Localization induced electron‐hole transition rate enhancement in GaAs quantum wells , 1984 .

[12]  R. Olshansky,et al.  Measurement of radiative and nonradiative recombination rates in InGaAsP and AlGaAs light sources , 1984 .

[13]  Frank Stern,et al.  Dispersion of the Index of Refraction Near the Absorption Edge of Semiconductors , 1964 .

[14]  Karl Hess,et al.  Temperature dependence of threshold current for a quantum-well heterostructure laser , 1980 .

[15]  Yasuhiko Arakawa,et al.  Theory of gain, modulation response, and spectral linewidth in AlGaAs quantum well lasers , 1985 .

[16]  H. Haug,et al.  Basic mechanisms of the optical nonlinearities of semiconductors near the band edge , 1985 .

[17]  Takeshi Kamiya,et al.  Recombination lifetime of carriers in GaAs‐GaAlAs quantum wells near room temperature , 1985 .

[18]  P. Melman,et al.  Screening of the electron-hole interaction in quantum well structures , 1985 .

[19]  C. Ell,et al.  Excitons and electron-hole plasma in quasi-two-dimensional systems☆ , 1985 .