Effect of Fe doping on optical properties of freestanding semi-insulating HVPE GaN:Fe

Solar blind metal-semiconductor-metal ultraviolet photodetectors using quasi-alloy of BGaN/GaN superlattices

“…The wavelength cutoff, corresponding to the value of the wavelength at which the responsivity is maximum, is found to be equal to 360 nm for the GaN-based PD and increases to values equal to 370 nm and 375 nm for the GaN:Fe-and BGaNbased PDs, respectively. This red-shift of the wavelength cutoff is due, in the case of GaN:Fe-based PD, to the absorption introduced by the density of states tails, and the Fe 3þ -ions incorporated in the GaN-lattice, 21 and, in the case of BGaN-based PD, as expected, to the band gap bowing induced by the boron incorporation. 22 For the BGaN-SLbased PD, according to this band gap bowing, a wavelength cutoff equal to 387 nm should be observed.…”

Optical nonlinearities and carrier dynamics in Fe doped GaN single crystal

“…11,16 An absorption peak at 458 nm is observed, which we identify as the 6 A 1 (S)-4 E(G) intracenter resonance absorption in the Fe 3þ ions. 11 Similar results were obtained in previous work, 16,17 demonstrating that Fe 3þ is a stable charge state in our GaN:Fe crystal. At picosecond regime, a reverse saturable absorption and self-defocusing behavior, which increase as the intensity increases, are observed.…”

“…15 Detailed studies of the optical absorption and reflectance of GaN:Fe versus the Fe doping were also presented. 16,17 As a deep acceptors, the lifetime of PL was modulated due to carrier trapping of Fe deep acceptors in GaN:Fe. 18 The above experimental and theoretical studies demonstrate the effect of the Fe doping on the linear optical properties and carrier dynamics under single photon excitation, but for one-photon excitation, the interference of surface recombination in GaN:Fe cannot be eliminated.…”

Metal-semiconductor-metal ultraviolet photodetectors directly fabricated on semi-insulating GaN:Fe template grown by hydride vapor phase epitaxy

“…1, compared with the transmission spectrum of the control MOCVD GaN sample, which exhibits a sharp transition edge at around 365 nm, corresponding the optical bandgap of GaN, the GaN:Fe template shows inferior optical quality with a gradual drop of transmittance from 450 nm to 365 nm. The parasitic light absorption of the GaN:Fe template in longer wavelength range should be caused by the native defects, Fe-induced structural defects and Fe impurity levels existing within the material [7]. Meanwhile X-ray diffraction measurement indicates that the high-resistivity GaN:Fe template has reasonable crystalline quality.…”