Growth and Characterization of InN Heteroepitaxial Layers Grown on Si Substrates by ECR-Assisted MBE

Abstract

For the first time, we observed strong band-edge photoluminescence at 1.814 eV, and two stronger emissions at 1.880 and 2.081 eV at 8.5 K from the respective 880 nm thick InN heteroepitaxial layers (heteroepilayers) with 10 nm thick InN buffer layers grown on Si(001) and Si(111) substrates by electron cyclotron resonance-assisted molecular beam epitaxy. The former was probably assigned as donor-to-acceptor pair (DAP(a-InN)) emission from wurtzite-InN (a-InN) crystal grains, the latter were assigned as donor bound exciton (D 0 X(a-InN)) emission, and D 0 X(b-InN) or DAP(b-InN) emission from zincblende-InN (b-InN) crystal grains, respectively. Substrate annealing before growth and the introduction of a buffer layer had strong influences on the crystal structure and crystalline quality of the initial InN heteroepilayers.

Characteristics of InN thin films grown using a PAMBE technique

“…This is not typical behaviour for a band edge transition, although the Moss-Burstein effect has been proposed as a means to reconcile the difference. There have been few reports of PL near 2 eV [6], and these show features having a full-width halfmaximum (FWHM) up to 0.5 eV-very broad for a band edge transition. On the other hand, most single crystalline films exhibit both absorption onsets and PL near 0.8 eV and the PL is much sharper, with FWHM as low as 35 meV being reported [7].…”

Visible emissions near 1.9–2.2 eV from hexagonal InN films grown by electron cyclotron resonance plasma-assisted molecular-beam epitaxy

“…observed by optical microscopy. The strong yellow PL emissions of the as-grown InN film were observed at around 2.2 eV as we have reported in previous papers [1,2]. The yellow emissions were observed from uniformly distributed (over an area of about 2 mm À2 ) localized spots several tens of mm in size (about 40 mm for example of Fig.…”

“…However, there have been few reports of yellow or red photoluminescence (PL) near 1.9-2.2 eV from InN films and bulk crystals, except for our previous data on InN films grown on Si substrates [1,2]. Very recently, several researchers have observed strong infrared PL emissions near 0.7-0.9 eV from a-InN films grown on c-plane sapphire (0 0 0 1) substrates with high crystalline quality [4][5][6].…”

MOVPE growth of InN buffer layers on sapphire

“…Another approach was to develop a similar know-how on InN buffer layers. This kind of buffer was investigated on various substrates like GaN [10], GaP [11], Si [12] or SiC [13], but mostly on sapphire [14][15][16][17]. These studies of the buffer layers are essentially based on characterization results of the main InN layer, grown on top of the buffer layer.…”