RT journal article
T1 AlN interlayer-induced reduction of dislocation density in the AlGaN epilayer
A1 Tobaldi, David M.
A1 Lajaunie, Luc Cyrille Jacques
A1 Cretì, A.
A1 Cuscunà, M.
A1 Tarantini, I.
A1 Esposito, M.
A1 Balestra, G.
A1 Lomascolo, M.
A1 Passaseo, A.
A1 Tasco, V.
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
AB The emerging ultrawide-bandgap AlGaN alloy system holds promise for the development of advanced materials in the next generation of power semiconductor and UV optoelectronic devices. Within this context, heterostructures based on III-nitrides are very popular in view of their applications as electronic and optoelectronic components. AlGaN-based deep UV emitters are gaining visibility due to their disinfection capabilities. Likewise, high electron mobility transistors are attracting increasing attention owing to their superior electron transport which yields high-speed and high-power applications. These devices are conventionally made of AlGaN/GaN heterostructures grown on foreign substrates. However, structural defects, including stress induced by a mismatch in unit cell parameters and the presence of dislocations, can not only decrease the efficiency of the light emitters (by facilitating the non-radiative recombination of electron-hole pairs), but also impede electron mobility within the two-dimensional electron gas at the AlGaN/GaN interface. Therefore, the significance of obtaining high-quality AlGaN layers becomes evident. Including a thin AlN interlayer between the GaN buffer layer and AlGaN is a possible answer to address these drawbacks. Not only do we show that a thin AlN layer, approximately ≤3 nm in thickness, between the GaN buffer and AlGaN layers, is effective in decreasing the dislocation densities in the AlGaN layer by around 30%, but also this is responsible for an increase in the electron mobility (approximately 33%) compared to a classical AlGaN/GaN heterostructure. Additionally, the resulting heterostructure exhibits better optical quality, with a 7-fold increase in intensity as well as a 20% reduction in full-width at half-maximum in the AlGaN emission.
PB Royal Society of Chemistry
SN 1466-8033
YR 2024
FD 2024
LK http://hdl.handle.net/10498/33754
UL http://hdl.handle.net/10498/33754
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 05-nov-2026