Transient studies of light emission from travelling space charge domains in GaAs and Ga1-xAlxAs

Balkan N., Hostut M.

PHYSICA B-CONDENSED MATTER, cilt.272, sa.1-4, ss.291-294, 1999 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 272 Sayı: 1-4
  • Basım Tarihi: 1999
  • Doi Numarası: 10.1016/s0921-4526(99)00290-2
  • Dergi Adı: PHYSICA B-CONDENSED MATTER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.291-294
  • Anahtar Kelimeler: hot electron light emission, impact ionisation, SPECTRUM
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

We report the results of our experimental studies concerning light emission (EL) from n-doped GaAs and Ga1-xAlxAs epilayers. EL is associated with impact ionisation within the travelling space charge domains (Gunn Domains) when the device is biased in the negative differential resistance (NDR) regime. A study of EL spectra has been carried out for devices with lengths in the range between 4 and 316 mu m. Our results combined with previous observations indicate that electron temperatures (T-e), obtained from the high-energy tail of the electroluminescence spectra by assuming a Maxwellian distribution have very strong dependence on the length (l) of the devices and can be fitted well on a universal T-e - l curve. For devices longer than 50 mu m observed electron temperatures can be explained using standard energy balance equations in the steady state where scattering with LO phonons is the dominant energy relaxation mechanism. For shorter devices, however the assumption regarding the thermalisation of hot electron population fails. (C) 1999 Elsevier Science B.V. All rights reserved.

We report the results of our experimental studies concerning light emission (EL) from n-doped GaAs and Ga(1-x)Al(x)As epilayers. EL is associated with impact ionisation within the travelling space charge domains (Gunn Domains) when the device is biased in the negative differential resistance (NDR) regime. A study of EL spectra has been carried out for devices with lengths in the range between 4 and 316 mu m. Our results combined with previous observations indicate that electron temperatures (T(e)), obtained from the high-energy tail of the electroluminescence spectra by assuming a Maxwellian distribution have very strong dependence on the length (l) of the devices and can be fitted well on a universal T(e) - l curve. For devices longer than 50 mu m observed electron temperatures can be explained using standard energy balance equations in the steady state where scattering with LO phonons is the dominant energy relaxation mechanism. For shorter devices, however the assumption regarding the thermalisation of hot electron population fails.