Highly sensitive ultraviolet photodetectors based on Mg-doped hydrogenated GaN films grown at 380 °C

Yagi, Satoshi

doi:10.1063/1.125749

Cited by 38 publications

(31 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Polycrystalline, 19 nanocrystalline, 20 and amorphous 37 GaN have also shown good luminescence characteristics. Applications of polycrystalline GaN films have been demonstrated in LEDs, 38,39 white lighting, 39 UV photodetectors, 40 solar cells, 41,42 thin film transistors, 43,44 and field electron emitters, 16,45 and suitability of GaN films for application in large area flat panel displays has also been explored. 46 The potential of GaN films for these applications has thus driven the search for low cost and low temperature deposition processes on low cost substrates.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target

Biswas

Bhattacharyya

Sahoo

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

Properties of InxGa1−xN films in terahertz range Appl. Phys. Lett. 100, 071913 (2012) Thermal carrier emission and nonradiative recombinations in nonpolar (Al,Ga)N/GaN quantum wells grown on bulk GaN J. Appl. Phys. 111, 033517 (2012) Surface depletion mediated control of inter-sub-band absorption in GaAs/AlAs semiconductor quantum well systems Appl. Phys. Lett. 100, 051110 (2012) High-Q optomechanical GaAs nanomembranes Appl. Phys. Lett. 99, 243102 (2011) Mg-induced terahertz transparency of indium nitride films Appl. Phys. Lett. 99, 232117 (2011) Additional information on J. Appl. Phys. GaN films have been deposited by reactive rf sputtering of GaAs target in 100% nitrogen ambient on quartz substrates at different substrate temperatures ranging from room temperature to 700°C. A series of films, from arsenic-rich amorphous to nearly arsenic-free polycrystalline hexagonal GaN, has been obtained. The films have been characterized by phase modulated spectroscopic ellipsometry to obtain the optical parameters, viz., fundamental band gap, refractive index, and extinction coefficient, and to understand their dependence on composition and microstructure. A generalized optical dispersion model has been used to carry out the ellipsometric analysis for amorphous and polycrystalline GaN films and the variation of the optical parameters of the films has been studied as a function of substrate temperature. The refractive index values of polycrystalline films with preferred orientation of crystallites are slightly higher ͑2.2͒ compared to those for amorphous and randomly oriented films. The dominantly amorphous GaN film shows a band gap of 3.47 eV, which decreases to 3.37 eV for the strongly c-axis oriented polycrystalline film due to the reduction in amorphous phase content with increase in substrate temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target

Biswas

Bhattacharyya

Sahoo

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…A disordered material grown at low temperatures using remote-plasma CVD has been shown to have potential for lighting and photodiode applications. 12,13 However, these studies only investigate the effect of changing one and sometimes two of the major sputterdeposition parameters in a controlled manner. In addition, attention is seldom paid to the deposition itself and to the level of oxygen contamination.…”

Section: Introductionmentioning

confidence: 99%

The properties and deposition process of GaN films grown by reactive sputtering at low temperatures

Knox-Davies

Shannon

Silva

2006

Journal of Applied Physics

View full text Add to dashboard Cite

Polycrystalline gallium nitride films, 100 nm to 1 m thick, were deposited under a range of conditions. Substrate electrode temperatures during sputtering were varied from room temperature to 450°C, the pressure from 0.15 to 6.0 Pa, the nitrogen fraction of the deposition atmosphere from 10% to 100% and the target bias from −400 to − 1800 V. The deposition rates as functions of these conditions are in the range 0.5-25 nm/ min. The growth rate is considered to be controlled respectively by the thermally activated desorption from the substrate, changes in the mean free path and concentration of gas particles, differences between the sputter yields of Ga and GaN in Ar and N 2 , and changes in the ion current and sputter yields. The films are generally columnar, with the grain size increasing with film thickness. The most crystalline films were grown at mid range temperatures, low N 2 concentrations, and low target biases, and the most disordered were grown at low pressures. The latter two cases suggest that decreasing the energy of particles incident on the film during deposition results in a more ordered film. The biaxial stress is compressive and shows an increasing trend with the target bias and N 2 concentration, reaching 4.7 GPa at 75% N 2 . Oxygen contamination of 3 -30 at. % has a major effect on the optical properties of the films, increasing the band gap values from 3.02 to Ͼ 4.0 eV and the Urbach tail energies from around 150 to 840 meV and decreasing the refractive index from 2.46 to 2.03. At a 40% N 2 deposition fraction, the N:Ga ratio is more or less constant at 1:1. Since the absolute oxygen incorporation rate changes very little, it is the relative film deposition rate which determines the final oxygen concentration. Excess Ga at low N 2 concentrations causes a decrease in the band gap and an increase in the Urbach tail energy.

show abstract

“…Anyway, the dangling or floating bonds create recombination and nonradiative centers, which are detrimental for the stability of the films. Although the hydrogen termination technique is generally applied to the amorphous GaN [1], it causes a decrease in the photoluminescence intensity [11]. The deposited a-GaN films were Ga-rich [7], which lead to the creation of dangling bonds from the Ga metal because the number of Ga atoms is larger than that of N atoms and Ga atoms are under coordinated.…”

Section: Discussionmentioning

confidence: 99%

“…Amorphous or polycrystalline GaN films are candidates for such light-emitting devices. Amorphous GaN (a-GaN)-based photodetectors have already been fabricated and commercialized [1]. We have investigated the amorphous and crystal GaN films deposited by means of the compound source molecular beam epitaxy (CS-MBE) technique for the fabrication of electroluminescent devices (ELDs) [2,3].…”

mentioning

confidence: 99%

Amorphous GaN:Zn films deposited by molecular beam deposition for blue electroluminescent devices

Honda

Shimanuki

Akiyama

et al. 2003

phys. stat. sol. (c)

View full text Add to dashboard Cite

The fabrication of Zn-doped amorphous GaN (a-GaN : Zn) films deposited on glass substrates is reported. The role of Zn in a-GaN films is also discussed with respect to light emission. A bluish photoluminescence peak at around 450 nm was observed from the a-GaN : Zn films at room temperature, which was not observed from the undoped a-GaN films. The emission intensity of a-GaN films was higher than that of undoped a-GaN films. This is due to the improvement of networks in amorphous films upon the introduction of Zn doping. The Zn doping of a-GaN films is effective for the fabrication of high-luminescent a-GaN films with a strong blue-light emission.

show abstract

Highly sensitive ultraviolet photodetectors based on Mg-doped hydrogenated GaN films grown at 380 °C

Cited by 38 publications

References 14 publications

Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target

Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target

The properties and deposition process of GaN films grown by reactive sputtering at low temperatures

Amorphous GaN:Zn films deposited by molecular beam deposition for blue electroluminescent devices

Contact Info

Product

Resources

About