On applicability of time-resolved optical techniques for characterization of differently grown 3C-SiC crystals and heterostructures
2012 (English)In: HETEROSIC and WASMPE 2011 / [ed] Daniel Alquier, Trans Tech Publications Inc., 2012, Vol. 711, 159-163 p.Conference paper (Refereed)
We applied a number of time-resolved optical techniques for investigation of optical and photoelectrical properties of cubic SiC grown by different technologies on different substrates. The excess carriers were injected by a short laser pulse and their dynamics was monitored by free-carrier absorption, light-induced transient grating, and photoluminescence techniques in a wide excitation range. Combining an optical and electrical probe beam delay, we found that free carrier lifetimes in differently grown layers vary from few ns up to 20 mu s. Temperature dependences of carrier diffusivity and lifetime revealed a pronounced carrier trapping in thin sublimation grown layers. In free-standing layers and thick sublimation layers, the ambipolar mobility was found the highest (120 cm(2)/Vs at room temperature). A linear correlation between the room-temperature band edge emission and carrier lifetime in differently grown layers was attributed to defect density, strongly dependent on the used growth conditions.
Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2012. Vol. 711, 159-163 p.
, Materials Science Forum, ISSN 0255-5476 ; 711
Cubic silicon carbide; light-induced transient grating; free carrier absorption; doping; mobility; carrier lifetime; carrier trapping
IdentifiersURN: urn:nbn:se:liu:diva-89787DOI: 10.4028/www.scientific.net/MSF.711.159ISI: 000302673900029OAI: oai:DiVA.org:liu-89787DiVA: diva2:609606
4th Workshop on Advanced Semiconductor Materials and Devices for Power Electronics Applications, 27-30 June 2011, Tours, France