Self-heating of silicon microwires: Crystallization and thermoelectric effects

Bakan G., Khan N., Cywar A., Cil K., Akbulut M., Gokirmak A., ...Daha Fazla

JOURNAL OF MATERIALS RESEARCH, cilt.26, sa.9, ss.1061-1071, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 9
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1557/jmr.2011.32
  • Dergi Adı: JOURNAL OF MATERIALS RESEARCH
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1061-1071
  • İstanbul Üniversitesi Adresli: Hayır

Özet

We describe experiments on self-heating and melting of nanocrystalline silicon microwires using single high-amplitude microsecond voltage pulses, which result in growth of large single-crystal domains upon resolidification. Extremely high current densities (>20 MA/cm(2)) and consequent high temperatures (1700 K) and temperature gradients (1 K/nm) along the microwires give rise to strong thermoelectric effects. The thermoelectric effects are characterized through capture and analysis of light emission from the self-heated wires biased with lower magnitude direct current/alternating current voltages. The hottest spot on the wires consistently appears closer to the lower potential end for n-type microwires and to the higher potential end for p-type microwires. The experimental light emission profiles are used to verify the mathematical models and material parameters used for the simulations. Good agreement between experimental and simulated profiles indicates that these models can be used to predict and design optimum geometry and bias conditions for current-induced crystallization of microstructures.