Characterisation of the electrical properties of solution‐grown GaN crystals by reflectivity and Hall measurements

Birkmann, B.; Salcianu, Carmen; Meissner, Η.; Hussy, S.; Friеdrich, J.; Müller, G.

doi:10.1002/pssc.200564119

Cited by 9 publications

(7 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…shown in dashed red. 22,23 The sharp absorption peaks observed in the measured spectrum between 3000 and 3250 cm À1 correspond well with previous experimental reports 6,8 and the calculated stretch vibration frequencies of V Ga -H complexes. 9,10 Broader absorption peaks at around 3350 cm À1 have not been previously reported from GaN.…”

Section: à3supporting

confidence: 90%

Infrared absorption of hydrogen-related defects in ammonothermal GaN

Suihkonen

Pimputkar

Speck

et al. 2016

Applied Physics Letters

View full text Add to dashboard Cite

Polarization controlled Fourier transform infrared (FTIR) absorption measurements were performed on a high quality m-plane ammonothermal GaN crystal grown using basic chemistry. The polarization dependence of characteristic absorption peaks of hydrogen-related defects at 3000–3500 cm−1 was used to identify and determine the bond orientation of hydrogenated defect complexes in the GaN lattice. Majority of hydrogen was found to be bonded in gallium vacancy complexes decorated with one to three hydrogen atoms (VGa-H1,2,3) but also hydrogenated oxygen defect complexes, hydrogen in bond-center sites, and lattice direction independent absorption were observed. Absorption peak intensity was used to determine a total hydrogenated VGa density of approximately 4 × 1018 cm−3, with main contribution from VGa-H1,2. Also, a significant concentration of electrically passive VGa-H3 was detected. The high density of hydrogenated defects is expected to have a strong effect on the structural, optical, and electrical properties of ammonothermal GaN crystals.

show abstract

Section: à3supporting

confidence: 90%

Infrared absorption of hydrogen-related defects in ammonothermal GaN

Suihkonen

Pimputkar

Speck

et al. 2016

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…[97,98] The absorbance of semiconductor material in the near infrared range is governed by the free carrier absorption, which can be modeled with the Drude model. [99,100] Using free carrier absorption obtained with the Drude model it is possible to determine the absolute absorption coefficients of peaks present in the spectra. [43] FTIR absorbance measurements with the free carrier effects removed on as grown ammonothermal GaN crystals are shown in …”

Section: Optical Absorption Measurements Of V Ga -Hmentioning

confidence: 99%

Defects in Single Crystalline Ammonothermal Gallium Nitride

Suihkonen

Pimputkar

Sintonen

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

Native bulk gallium nitride (GaN) has emerged as an alternative for sapphire and silicon as a substrate material for III‐N devices. While quasi‐bulk GaN substrates are currently commercially available, single crystal GaN substrates are considered essential for future high performance light emitters and power devices. The ammonothermal method is currently considered one of the most feasible methods to grow large truly bulk crystals of GaN at low cost and high structural quality. High crystalline quality GaN substrates sliced from ammonothermally grown crystals have been demonstrated and utilized in homoepitaxy for III‐N devices. However, despite the high crystalline quality the properties of as‐grown ammonothermal GaN crystals and substrates are affected by the presence of impurities and other defects that hinder their use for device applications. Here, the main developments of ammonothermal growth of GaN and the effects of impurities, native point defects, and dislocations on the material properties are summarized. Additionally, measurement techniques that enable the evaluation of point defect concentration and low dislocation density distribution over a large area on bulk GaN substrates are reviewed.

show abstract

“…The charge carrier concentration (n-type) of the LPSG layers is n ¼ 4 Â 10 19 cm À3 and the mobility m ¼ 70-80 cm 2 /V s [8].…”

Section: Article In Pressmentioning

confidence: 99%