Regensburg 2025 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 32: Nitrides: Preparation and Characterization I

HL 32.6: Talk

Wednesday, March 19, 2025, 10:45–11:00, H15

Measuring solute concentrations in ammonothermal solutions via in situ X-ray absorption - estimating detection limits for novel nitrides — •Rajesh Chirala, Ege N. Civas, and Saskia Schimmel — Chair of Electron Devices (LEB), Dept. EEI, FAU Erlangen-Nürnberg, Cauerstr. 6, 91058 Erlangen, Germany

The ammonothermal method [1] is effective for producing high quality single crystals of binary and ternary nitrides [2], which are emerging semiconductor materials [3]. Despite the challenging process conditions (100 to 300 MPa, 400 to 800 °C), in situ measurement techniques such as X-ray imaging [4] allow to study reaction kinetics and solubilities, which are highly relevant to bulk crystal growth. In case of GaN, the quantitative determination of the concentration of Ga containing intermediates was already demonstrated [5].

By simulating the X-ray absorption of novel nitrides in an ammonothermal autoclave, we estimate element-specific detection limits for solute concentrations and derive strategies for detecting lighter elements or lower concentrations. Amongst the others, effectiveness of using a combination of lower X-ray energies and higher X-ray dose will be analyzed.

References :-

[1] R. Dwilinski et al., Acta Phys. Pol. A 88, 833, 1995.

[2] J. Häusler, W. Schnick, Chemistry 24, 11864, 2018.

[3] D. Jena et al., Jpn. J. Appl. Phys. 58, SC0801, 2019.

[4] S. Schimmel et al., J. Cryst. Growth 418, 64, 2015.

[5] S. Schimmel et al., J. Cryst. Growth 498, 214, 2018.

Keywords: x-ray absorption; Ammonothermal method; Nitrides; in situ monitoring; crystal dissolution