Influence of different atmospheres on the life time of porous silicon light-emitting devices

B. R. Jumayev*, Hoi Lam Tam, Kok Wai Cheah, N. E. Korsunska

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review


In present report, we investigated the degradation processes in porous silicon light-emitting devices (LED) in different atmospheres (O2, N2, air and vacuum) by photoluminescence (PL), electroluminescence (EL), lifetime (LT) and I-V characteristic measurements as well as by Energy Dispersive X-ray Spectroscopy (EDS). The contacts were made by evaporation of Au and Au/Cu alloy. The LEDs emit in visible range at forward and reverse bias. As a rule, full width at half maximum of EL spectrum is wider than that of PL spectrum. The bias direction of applied voltage during degradation change EL, PL, I-V characteristics, and LT of the LEDs. At forward bias, LT degradation is less than that in reverse bias. The degradation of LEDs during forward bias did not produce any change in the spectral shape of EL and PL. At reverse bias, degradation led to red shift in the peak of EL and PL. The results show that the lifetime of LEDs with Au contact is longer than Au-Cu. Operating in different atmospheres, the LT in vacuum is longest and is more than 100 hours in reverse bias at room temperature. Possible mechanisms of degradation of LEDs are discussed. It is proposed that degradation is connected mainly with two processes: oxidation and metal diffusion. It is shown that the oxygen and metal in ionic state can diffuse quickly. Hence, in forward bias, the diffusion of metal would dominate, and in reverse bias, diffusion of oxygen dominates.

Original languageEnglish
Pages (from-to)685-690
Number of pages6
JournalMaterials Research Society Symposium Proceedings
Publication statusPublished - 2003
EventQuantum Confined Semiconductor Nanostructures - Boston MA, United States
Duration: 2 Dec 20025 Dec 2002

Scopus Subject Areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Influence of different atmospheres on the life time of porous silicon light-emitting devices'. Together they form a unique fingerprint.

Cite this