Metal halide perovskites (MHPs) have emerged as a frontrunner semiconductor technology for application in third generation photovoltaics while simultaneously making significant strides in other areas of optoelectronics. Photodetectors are one of the latest additions in an expanding list of applications of this fascinating family of materials. The extensive range of possible inorganic and hybrid perovskites coupled with their processing versatility and ability to convert external stimuli into easily measurable optical/electrical signals makes them an auspicious sensing element even for the high‐energy domain of the electromagnetic spectrum. Key to this is the ability of MHPs to accommodate heavy elements while being able to form large, high‐quality crystals and polycrystalline layers, making them one of the most promising emerging X‐ray and γ‐ray detector technologies. Here, the fundamental principles of high‐energy radiation detection are reviewed with emphasis on recent progress in the emerging and fascinating field of metal halide perovskite‐based X‐ray and γ‐ray detectors. The review starts with a discussion of the basic principles of high‐energy radiation detection with focus on key performance metrics followed by a comprehensive summary of the recent progress in the field of perovskite‐based detectors. The article concludes with a discussion of the remaining challenges and future perspectives.

Inorganic and organic-inorganic (hybrid) perovskite semiconductor materials have attracted worldwide scientific attention and research effort as the new wonder semiconductor material in optoelectronics. Their excellent physical and electronic properties have been exploited to boost the solar cells efficiency beyond 23% and captivate their potential as competitors to the dominant silicon solar cells technology. However, the fundamental principles in Physics, dictate that an excellent direct band gap material for photovoltaic applications must be also an excellent light emitter candidate. This has been realized for the case of perovskite-based light emitting diodes (LEDs) but much less for the case of the respective laser devices. Here, the strides, exclusively in lasing, made since 2014 are presented for the first time. The solution processability, low temperature crystallization, formation of nearly defect free, nanostructures, the long range ambipolar transport, the direct energy band gap, the high spectral emission tunability over the entire visible spectrum and the almost 100% external luminescence efficiency show perovskite semiconductors’ potential to transform the nanophotonics sector. The operational principles, the various adopted material and laser configurations along the future challenges are reviewed and presented in this paper.

Hybrid lead halide spin coated perovskite films have been successfully tested as portable, flexible, operated at room temperature, self-powered, and ultrasensitive ozone sensing elements. The electrical resistance of the hybrid lead mixed halide perovskite (CH₃NH₃PbI_3–xCl_x) sensing element, was immediately decreased when exposed to an ozone (O₃) environment and manage to recover its pristine electrical conductivity values within few seconds after the complete removal of ozone gas. The sensing measurements showed different response times at different gas concentrations, good repeatability, ultrahigh sensitivity and fast recovery time. To the best of our knowledge, this is the first time that a lead halide perovskite semiconductor material is demonstrating its sensing properties in an ozone environment. This work shows the potential of hybrid lead halide based perovskites as reliable sensing elements, serving the objectives of environmental control, with important socioeconomic impact.

Literature review of metal and rare-earth-element nanoparticles doped in the device building blocks of mesoscopic and planar perovskite solar cells.

Start-up development, success, and sustainability are affected by contextual factors that constitute a regional entrepreneurship ecosystem. Based on previous literature, we propose the conceptual framework Start-Up Ecosystem (StUpEco) that highlights the contextual drivers of a start-up business affected by the entrepreneurial ecosystem entities involved within the quadruple helix model. Furthermore, the proposed framework is tested according to the perceptions of Greek start-uppers through an empirical survey. According to our findings, the start-uppers’ motivation is explained mainly through opportunity rather than necessity. The study identifies government issues, such as tax incentives and acceleration of starting procedures, availability of funding opportunities, connectivity of stakeholders, entrepreneurship education, previous start-up experience, incubator support, as well as mentoring, as the most significant issues affecting the successful development of start-ups.