Professor Buddhika Mendis' Outputs (81)

Inelastic Scattering in Electron Backscatter Diffraction and Electron Channeling Contrast Imaging (2020)
Journal Article
Mendis, B. G., Barthel, J., Findlay, S. D., & Allen, L. J. (2020). Inelastic Scattering in Electron Backscatter Diffraction and Electron Channeling Contrast Imaging. Microscopy and Microanalysis, 26(6), 1147-1157. https://doi.org/10.1017/s1431927620024605

Electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) are used to extract crystallographic information from bulk samples, such as their crystal structure and orientation as well as the presence of any dislocation and... Read More about Inelastic Scattering in Electron Backscatter Diffraction and Electron Channeling Contrast Imaging.

Microscopic Analysis of Interdiffusion and Void Formation in CdTe(1–x)Sex and CdTe Layers (2020)
Journal Article
Baines, T., Bowen, L., Mendis, B. G., & Major, J. D. (2020). Microscopic Analysis of Interdiffusion and Void Formation in CdTe(1–x)Sex and CdTe Layers. ACS Applied Materials and Interfaces, 12(34), 38070-38075. https://doi.org/10.1021/acsami.0c09381

The use of CdSe layers has recently emerged as a route to improving CdTe photovoltaics through the formation of a CdTe(1–x)Sex (CST) phase. However, the extent of the Se diffusion and the influence it has on the CdTe grain structure has not been wide... Read More about Microscopic Analysis of Interdiffusion and Void Formation in CdTe(1–x)Sex and CdTe Layers.

Theory underpinning multislice simulations with plasmon energy losses (2020)
Journal Article
Mendis, B. (2020). Theory underpinning multislice simulations with plasmon energy losses. Microscopy, 69(3), 173-175. https://doi.org/10.1093/jmicro/dfaa003

The theoretical conditions for small-angle inelastic scattering where the incident electron can effectively be treated as a particle moving in a uniform potential is examined. The motivation for this work is the recent development of a multislice met... Read More about Theory underpinning multislice simulations with plasmon energy losses.

Angular dependence of fast-electron scattering from materials (2020)
Journal Article
Barthel, J., Cattaneo, M., Mendis, B. G., Findlay, S. D., & Allen, L. J. (2020). Angular dependence of fast-electron scattering from materials. Physical Review B, 101(18), Article 184109. https://doi.org/10.1103/physrevb.101.184109

Angular resolved scanning transmission electron microscopy is an important tool for investigating the properties of materials. However, several recent studies have observed appreciable discrepancies in the angular scattering distribution between expe... Read More about Angular dependence of fast-electron scattering from materials.

Evidence for Self-healing Benign Grain Boundaries and a Highly Defective Sb2Se3–CdS Interfacial Layer in Sb2Se3 Thin-Film Photovoltaics (2020)
Journal Article
Williams, R. E., Ramasse, Q. M., McKenna, K. P., Phillips, L. J., Yates, P. J., Hutter, O. S., Durose, K., Major, J. D., & Mendis, B. G. (2020). Evidence for Self-healing Benign Grain Boundaries and a Highly Defective Sb2Se3–CdS Interfacial Layer in Sb2Se3 Thin-Film Photovoltaics. ACS Applied Materials and Interfaces, 12(19), 21730-21738. https://doi.org/10.1021/acsami.0c03690

The crystal structure of Sb2Se3 gives rise to unique properties that cannot otherwise be achieved with conventional thin-film photovoltaic materials, such as CdTe or Cu(In,Ga)Se2. It has previously been proposed that grain boundaries can be made beni... Read More about Evidence for Self-healing Benign Grain Boundaries and a Highly Defective Sb2Se3–CdS Interfacial Layer in Sb2Se3 Thin-Film Photovoltaics.

Electron Compton scattering and the measurement of electron momentum distributions in solids (2020)
Journal Article
Talmantaite, A., Hunt, M., & Mendis, B. (2020). Electron Compton scattering and the measurement of electron momentum distributions in solids. Journal of Microscopy, 279(3), 185-188. https://doi.org/10.1111/jmi.12854

Electron Compton scattering is a technique that gives information on the electron momentum density of states and is used to characterize the ground state electronic structure in solids. Extracting the momentum density of states requires us to assume... Read More about Electron Compton scattering and the measurement of electron momentum distributions in solids.

An inelastic multislice simulation method incorporating plasmon energy losses (2019)
Journal Article
Mendis, B. (2019). An inelastic multislice simulation method incorporating plasmon energy losses. Ultramicroscopy, 206, Article 112816. https://doi.org/10.1016/j.ultramic.2019.112816

Quantitative electron microscopy requires accurate simulation methods that take into account both elastic and inelastic scattering of the high energy electrons within the specimen. Here a method to combine plasmon excitations, the dominant energy los... Read More about An inelastic multislice simulation method incorporating plasmon energy losses.

Planck's generalised radiation law and its implications for cathodoluminescence spectra (2019)
Journal Article
Mendis, B. (2019). Planck's generalised radiation law and its implications for cathodoluminescence spectra. Ultramicroscopy, 204, 73-80. https://doi.org/10.1016/j.ultramic.2019.05.007

Cathodoluminescence (CL) is an important analytical technique for probing the optical properties of materials at high spatial resolution. Interpretation of CL spectra is however complicated by the fact that the spectrum depends on the carrier injecti... Read More about Planck's generalised radiation law and its implications for cathodoluminescence spectra.

Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells (2019)
Journal Article
Fiducia, T. A., Mendis, B. G., Li, K., Grovenor, C. R., Munshi, A. H., Barth, K., Sampath, W. S., Wright, L. D., Abbas, A., Bowers, J. W., & Walls, J. M. (2019). Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells. Nature Energy, 4, 504-511. https://doi.org/10.1038/s41560-019-0389-z

Electricity produced by cadmium telluride (CdTe) photovoltaic modules is the lowest-cost electricity in the solar industry, and now undercuts fossil fuel-based sources in many regions of the world. This is due to recent efficiency gains brought about... Read More about Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells.

Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells (2019)
Journal Article
Mendis, B. (2019). Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells. Semiconductor Science and Technology, 34(5), Article 055008. https://doi.org/10.1088/1361-6641/ab0c2b

The interface between the emitter and absorber layers in a thin-film solar cell must satisfy two important criteria, namely a small lattice mismatch and electron barrier height. It is shown that the barrier height is lowered when the emitter is fully... Read More about Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells.

Optical Properties and Dielectric Functions of Grain Boundaries and Interfaces in CdTe Thin-Film Solar Cells (2019)
Journal Article
Mendis, B. G., Ramasse, Q. M., Shalvey, T., Major, J. D., & Durose, K. (2019). Optical Properties and Dielectric Functions of Grain Boundaries and Interfaces in CdTe Thin-Film Solar Cells. ACS Applied Energy Materials, 2(2), 1419-1427. https://doi.org/10.1021/acsaem.8b01995

CdTe thin-film solar cells have complex microstructures, such as grain boundaries within the absorber layer, as well as CdS window, and Au back contact interfaces, where the local structure and chemistry undergo significant changes. The optical prope... Read More about Optical Properties and Dielectric Functions of Grain Boundaries and Interfaces in CdTe Thin-Film Solar Cells.

Novel synthesis and properties of hydrogen-free detonation nanodiamond (2018)
Journal Article
Batsanov, S. S., Osavchuk, A. N., Naumov, S. P., Gavrilkin, S. M., Leskov, A. S., Mendis, B. G., Beeby, A., & Batsanov, A. S. (2018). Novel synthesis and properties of hydrogen-free detonation nanodiamond. Materials Chemistry and Physics: Including Materials Science Communications, 216, 120-129. https://doi.org/10.1016/j.matchemphys.2018.05.072

Practically hydrogen-free nanodiamond (HFND), a prospective neutron-optical material, was prepared (in up to 3% yield) by detonating pure or graphite-doped RDX in an ice shell and comprehensively characterized by elemental analysis, X-ray diffraction... Read More about Novel synthesis and properties of hydrogen-free detonation nanodiamond.

Crystal structure and anti-site boundary defect characterisation of Cu2ZnSnSe4 (2017)
Journal Article
Mendis, B., McKenna, K., Gurieva, G., Rumsey, M., & Schorr, S. (2018). Crystal structure and anti-site boundary defect characterisation of Cu2ZnSnSe4. Journal of Materials Chemistry A: materials for energy and sustainability, 6(1), 189-197. https://doi.org/10.1039/c7ta08263k

The crystal structure identification of the photovoltaic material Cu2ZnSnSe4 (CZTSe) is challenging due to the distinguishing feature between the two polymorphs, kesterite and stannite, being the arrangement of Cu and Zn ions. Here an energy dispersi... Read More about Crystal structure and anti-site boundary defect characterisation of Cu2ZnSnSe4.

Nanometre-scale optical property fluctuations in Cu2ZnSnS4 revealed by low temperature cathodoluminescence (2017)
Journal Article
Mendis, B., Taylor, A., Guennou, M., Berg, D., Arasimowicz, M., Ahmed, S., …Dale, P. (2018). Nanometre-scale optical property fluctuations in Cu2ZnSnS4 revealed by low temperature cathodoluminescence. Solar Energy Materials and Solar Cells, 174, 65-76. https://doi.org/10.1016/j.solmat.2017.08.028

Band tailing is a major contributing factor to the large open circuit voltage (Voc) deficit that is currently limiting Cu2ZnSnS4 (CZTS) photovoltaic devices. It occurs in highly doped, highly compensated semiconductors and gives rise to a non-uniform... Read More about Nanometre-scale optical property fluctuations in Cu2ZnSnS4 revealed by low temperature cathodoluminescence.

The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils (2016)
Journal Article
Mendis, B., Howkins, A., Stowe, D., Major, J., & Durose, K. (2016). The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils. Ultramicroscopy, 167, 31-42. https://doi.org/10.1016/j.ultramic.2016.05.002

There is renewed interest in cathodoluminescence (CL) in the transmission electron microscope, since it can be combined with low energy loss spectroscopy measurements and can also be used to probe defects, such as grain boundaries and dislocations, a... Read More about The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils.

The effects of junction interdiffusion and misfit dislocations on the efficiency of highly mismatched heterojunction photovoltaic devices (2016)
Journal Article
Mendis, B., Treharne, R., Lane, D., & Durose, K. (2016). The effects of junction interdiffusion and misfit dislocations on the efficiency of highly mismatched heterojunction photovoltaic devices. Applied Physics Letters, 108(18), Article 183505. https://doi.org/10.1063/1.4948397

A general modelling methodology has been developed to evaluate the effects of chemical interdiffusion and misfit dislocations on the performance of heterojunction solar cells made from highly mismatched materials. Results for the exemplar materials s... Read More about The effects of junction interdiffusion and misfit dislocations on the efficiency of highly mismatched heterojunction photovoltaic devices.

Understanding quaternary compound Cu2ZnSnSe4 synthesis by microscopic scale analyses at an identical location (2016)
Journal Article
Crossay, A., Colombara, D., Melchiorre, M., Guennou, M., Mendis, B., & Dale, P. (2016). Understanding quaternary compound Cu2ZnSnSe4 synthesis by microscopic scale analyses at an identical location. Journal of Materials Chemistry C Materials for optical and electronic devices, 4(21), 4626-4629. https://doi.org/10.1039/c6tc01114d

The synthesis of multinary compound films from layered precursors is only partially understood. Identical location microscopy resolves the multi-step synthesis of Cu2ZnSnSe4 from metallic stacks on the micron-scale. Large scale metal alloying and the... Read More about Understanding quaternary compound Cu2ZnSnSe4 synthesis by microscopic scale analyses at an identical location.

Direct growth of Si nanowires on flexible organic substrates (2016)
Journal Article
Tian (田琳), L., Di Mario, L., Minotti, A., Tiburzi, G., Mendis, B. G., Zeze, D. A., & Martelli, F. (2016). Direct growth of Si nanowires on flexible organic substrates. Nanotechnology, 27(22), Article 225601. https://doi.org/10.1088/0957-4484/27/22/225601

A key characteristic of semiconductor nanowires (NWs) is that they grow on any substrate that can withstand the growth conditions, paving the way for their use in flexible electronics. We report on the direct growth of crystalline silicon nanowires o... Read More about Direct growth of Si nanowires on flexible organic substrates.

Long lifetime hole traps at grain boundaries in CdTe thin-film photovoltaics (2015)
Journal Article
Mendis, B., Gachet, D., Major, J., & Durose, K. (2015). Long lifetime hole traps at grain boundaries in CdTe thin-film photovoltaics. Physical Review Letters, 115(21), Article 218701. https://doi.org/10.1103/physrevlett.115.218701

A novel time-resolved cathodoluminescence method, where a pulsed electron beam is generated via the photoelectric effect, is used to probe individual CdTe grain boundaries. Excitons have a short lifetime (≤100  ps ) within the grains and are rapidly... Read More about Long lifetime hole traps at grain boundaries in CdTe thin-film photovoltaics.

On the electron vortex beam wavefunction within a crystal (2015)
Journal Article
Mendis, B. (2015). On the electron vortex beam wavefunction within a crystal. Ultramicroscopy, 157, 1-11. https://doi.org/10.1016/j.ultramic.2015.05.004

Electron vortex beams are distorted by scattering within a crystal, so that the wavefunction can effectively be decomposed into many vortex components. Using a Bloch wave approach equations are derived for vortex beam decomposition at any given depth... Read More about On the electron vortex beam wavefunction within a crystal.