Raman measurements on GaN thin films for PV - purposes

Structural and Optical Properties of GaN Thin Films Grown on Si (111) by Pulsed Laser Deposition

“…The high energy side of the PL spectrum, above 3.0 eV, of GaN film, at 10K, is shown in Figure 5. It can be seen additional PL structures located at 3.362, 3.293, 3.223, 3.154 eV, which are separated 69 meV from each other, these three regular spaced structures account for the coupling of phonons to the PL emission at 3.362 eV, moreover the respective vibrational frequency corresponds to the transversal optical phonon (TO) designated as E 1 with a frequency of 559 cm -1 24 . This coupling of TO phonon, E 1 , in GaN, has been also reported by Z. Chen et al 25 , in GaN grown by MOCVD on Al 2 O 3 substrates.…”

“…The nitride semiconductors, particularly GaN, have useful applications as light-emitting devices and as robust semiconductors for possible uses in transparent microelectronics 1 . Most of the best quality thin films are produced by molecular beam epitaxy (MBE) or metalorganic chemical vapour deposition (MOCVD), thus the exploration of fast and not so expensive techniques, like sublimation 2 or PLD [3][4][5][6] , that makes possible to obtain good quality materials, results of interest for the materials science community. With PLD technique is possible to grow thin films into high vacuum level, at low substrate temperatures and at fast growth rate of the order of Å/pulse, to obtain stoichiometric films.…”

Optical Characteristics of GaN Thin Film Deposited by Pulsed Laser Ablation 

“…In addition to that, some of the presented technologies used for deposition of the semiconductor IIInitrides nanostructures like metal-organic chemical vapor deposition and the hydride vapor phase epitaxy method include precursors of toxic and flammable [33][34][35][36]. Thereafter, scientific researchers need to pay special attention to chemical safety, chemical waste disposal and the cost spent on the equipment and maintenance, etc [37][38][39][40]. Therefore, due to the importance of this topic, it requires finding safe, simple, and inexpensive methods that are alternative and capable of growing thin and high-efficiency films as a successful alternative to previously used techniques such as pulsed laser deposition and pulsed laser ablation in liquid technology and this will be presented here as a new and safe technology…”