I am a PhD student in Physics at University of Dundee, Scotland, United Kingdom. Currently, I have been focusing on atomic level point defect identification in nuclear materials, metal halide perovskites as well as other semiconductor materials using positron annihilation spectroscopy techniques.

I did my Bachelor of Science in Physics, Chemistry, and Mathematics (PCM) from MJP Rohilkhand University, India. Thereafter, I have completed Master of Physics from Indian Institute of Technology Jodhpur, India. After this, I moved to Scotland, UK for my doctoral studies.

My master's dissertation was on the ”Perovskite oxide based solar selective absorber coating for solar thermal applications”. The role of solar selective absorber coatings (SSACs) to convert solar energy directly into thermal energy and frequently used for power generation, space and water heating. In addition, the SSACs are designed to have high absorptance (ideally ∼100%) in the UV-vis to near infrared region (0.3–2.5 µm) and low emittance (ideally ∼0%) in the infrared region (2.5–25 µm). During this project I synthesized two Perovskite oxide materials BiFeO₃, BaTiO₃ and also did thermal oxidation test on stainless steel.

I have two first auther research papers from my MSc project, first was published in "Sustainable Energy and Fuels" RSC Journal and second was published in "Solar Energy" Elsevier Journal.

• Singh, Aryaveer, et al. "BiFeO₃ perovskite-based all oxide ambient stable spectrally selective absorber coatings for solar thermal application." Sustainable Energy & Fuels 8.12 (2024): 2762-2776.
• Singh, Aryaveer, et al. "Thermally treated pristine and BaTiO₃ coated stainless steel as an efficient spectrally selective absorber for photothermal application." Solar Energy 287 (2025): 113260.

• Positron Physics
• Positron annihilation techniques
• Energy Materials
• Metal halide perovskites
• Point Defects
• Solar Thermal

In materials science, positron annihilation offers sensitive and adaptable probing techniques that may characterise electronic structure and vacancy-type, openvolume, and defect characteristics. The methods make use of the data that the photons carrying out the quantum relativistic process of a positron's annihilation with electron, its antiparticle. The electron density of the local environment examined determines how long it will take for the implanted positron to annihilate with a host electron. The conversion to two anticolinear γ-photons that occurs during annihilation typically provides information about the electron's electrical characteristics as well as the momentum of the electron-positron pair at the time of annihilation.

The positron (e⁺) is a first anti-particle discovered in physics history. It has positive charged with same mass and spin as electron. The existence of positron theoretically predicted by P. A. M. Dirac in 1928 as an explanation of negative energy solutions of his quantum theory of electron, his investigations came from the relativistically invariant wave equation. After few years later, in 1932, American physicist Carl D. Anderson experimentally discovered positron, while studying cosmic ray using a Wilson cloud-chamber. He observed that a particle tracks in cloud chamber is identical to expected electron with mass to charge ratio, but the particle tracks curved in the opposite direction which indicated that presence of particle with positive charge.

Positron annihilation in matter was first studied in the 1940s. These studies led to the discovery of the Doppler broadening of the 511 keV annihilation γ-ray energy spectrum, and to the observation of deviations from anticollinearity of the two γ-annihilation event photons, both due to the momentum distribution of the positron–electron (e⁺ e^-) pairs (Beringer and Montgomery 1942; DeBenedetti et al., 1949; DeBenedetti et al., 1950).

A further major breakthrough occurred in the late 1960s when it was established that positron annihilation was capable of detecting vacancy-type defects with high sensitivity. For instance, MacKenzie et al. reported a reversible temperature dependence in the e⁺ lifetime of low melting-temperature metals, which was attributed to the interaction of positrons with vacant lattice sites (MacKenzie et al., 1967). A quantitative interpretation of these results followed, based on what came to be known as the two-state, standard, trapping model (Bergersen and Stott 1969; Connors and West 1969). It was also realized that the results of earlier studies of the angular correlation of annihilation radiation on plastically deformed metals (Dekhtyar et al., 1964) could be understood in terms of e⁺ trapping at crystal defects.

For further details,

Keeble, D. J., Brossmann, U., Puff, W., & Wurschum, R. (2012). Positron annihilation studies of materials. https://doi.org/10.1002/0471266965