• Energy Research

Abstract Pnictogen chalcohalides are semiconductors that have emerged as promising materials for energy conversion due to their exceptional optoelectronic properties. Their electronic configuration (ns2), particularly for Bi- and Sb-based compounds, can be a key factor in efficient carrier transport and defect tolerance, similarly, to Pb-perovskites. In the present study, the Bi-containing chalcohalide, bismuth selenoiodide (BiSeI) was synthesized via isothermal heat treatment of binary precursors in evacuated quartz ampoules. The synthesized BiSeI microcrystals exhibited a characteristic needle-like morphology and a near-stoichiometric composition. Both indirect and direct band gap energies of BiSeI were determined by ultraviolet–visible–near-infrared diffuse reflectance spectroscopy, with room temperature values of 1.17 eV and 1.29 eV, respectively. This study presents the first experimental investigation of the photoluminescence properties of BiSeI microcrystals resulting in a recombination model involving multiple defect states. This work provides valuable insights into the defect structure and recombination mechanisms within BiSeI, paving the way for further exploration of its potential in optoelectronic devices.

This dataset entails various structural material data that was used to provide additional evidence for arguments presented in publication "Deposition of Sn-Zr-Se precursor by thermal evaporation and PLD for the synthesis of SnZrSe3 thin films". Mainly data consists of: SEM, XRD, Raman, Auger and TGA raw data. Summary of results is provided in Extended_data.pdf file

This is the pdf copy of the publication entitled "Synthesis and physical characteristics of narrow bandgap chalcogenide SnZrSe3 [version 2; peer review: 2 approved]" by R. Kondrotas et al, including the reviewers' comments and authors' reponse.

AbstractCuZnInSe3 (CZISe) is an interesting alternative for the acknowledged Cu(In,Ga)Se2 absorber layer in thin film solar cells. While the partial replacement of scarce and expensive indium and gallium by zinc decreases manufacturing costs, the solid solution between CuInSe2 and ZnSe opens interesting options for band gap tuning and grading. Its potential as an absorber layer in photovoltaic devices has been demonstrated by obtaining 7.4 and 7.6 % efficiency in CZISSe‐ and CZISe‐based devices, respectively. On the other hand, the inherent complexity of the quaternary CZISe together with a lack of fundamental insights puts a limit to its current development. We present insights on the influence of the copper content ([Cu]/([Zn] + [In]) ratio) on the structural and optoelectronic properties of CZISe as well as the formation of secondary phases. By means of XRD and Raman scattering analyses, in addition to the sphalerite CZISe structure, a chalcopyrite Cu‐In‐Zn‐Se phase was found for high copper concentrations. On the contrary, for low Cu concentrations, unambiguous indications of a new ordered vacancy compound (OVC)–like phase formation both in XRD patterns and in Raman spectra were found. Conditions of pre‐resonant Raman scattering were applied to emphasize the new found phase and to estimate its concentration. Finally, the influence of each phase on the optoelectronic parameters and performance of solar cells with efficiencies of up to 7.4 % was studied.

Background: The development of organic/inorganic metal halide perovskites has seen unprecedent growth since their first recognition for applications in optoelectronic devices. However, their thermodynamic stability and toxicity remains a challenge considering wide-scale deployment in the future. This spurred an interest in search of perovskite-inspired materials which are expected to retain the advantageous material characteristics of halide perovskites, but with high thermodynamic stability and composed of earth-abundant and low toxicity elements. ABX3 chalcogenides (A, B=metals, X=Se, S) have been identified as potential class of materials meeting the aforementioned criteria. Methods: In this work, we focus on studying tin zirconium selenide (SnZrSe3) relevant physical properties with an aim to evaluate its prospects for application in optoelectronics. SnZrSe3 powder and monocrystals were synthesized via solid state reaction in 600 – 800 °C temperature range. Crystalline structure was determined using single crystal and powder X-ray diffraction methods. The bandgap was estimated from diffused reflectance measurements on powder samples and electrical properties of crystals were analysed from temperature dependent I-V measurements. Results: We found that SnZrSe3 crystals have a needle-like structure (space group – Pnma) with following unit cell parameters: a=9.5862(4) Å, b=3.84427(10) Å, c=14.3959(5) Å. The origin of the low symmetry crystalline structure was associated with stereochemical active electron lone pair of Sn cation. Estimated bandgap was around 1.15 eV which was higher than measured previously and predicted theoretically. Additionally, it was found that resistivity and conductivity type depended on the compound chemical composition. Conclusions: Absorption edge in the infrared region and bipolar dopability makes SnZrSe3 an interesting material candidate for application in earth-abundant and non-toxic single/multi-junction solar cells or other infrared based optoelectronic devices.

This dataset contains underlying data of publication entitled "Synthesis and physical characteristics of narrow bandgap chalcogenide SnZrSe3". Data comprises: -Sample description.txt (synthesis conditions of the sample presented in the publication) -F1IS_V_6244.cif (crystallographic information file about SnZrSe3 structure as determined by single-crystal XRD method). - XRD.zip (raw XRD patterns of powder samples presented in the publication in .ras and .raw formats). -Raman.zip (raw Raman spectra in .txt format and OriginPro project file where data was processed and plotted). -Optics.zip (raw diffuse reflectance data in .txt format and OriginPro project file where data was processed and plotted). -JV-T.zip (J-V curves at specific temperature in .txt format and OriginPro project files where data was processed and plotted). -Images.zip (optical photographs of the sample and untreated SEM images of SnZrSe3 crystals). -Extented data.pdf (additional information supporting claims in the publication with direct link to the main text, such as figures).

The bandgap of SnZrSe3 was successfully engineered by cationic substitution to create novel materials photoactive in the short wavelength infrared region.