Influence of Helium-Neon Laser Irradiation on Seed Germination In Vitro and Physico-Biochemical Characters in Seedlings of Brinjal (Solanum melongena L.) var. Mattu Gulla

In the present study, the seeds of brinjal (Solanum melongena L.) var. Mattu Gulla were irradiated with single exposure of He–Ne laser at different doses of 5–40 J cm^?2 and germinated aseptically. Thirty day old seedlings were harvested and the germination, growth, physiological and biochemical parameters were estimated and compared with un‐irradiated control seedlings. A significant enhancement in growth characters were noted with respect to length, fresh and dry weight of shoots and roots. In addition, chlorophyll (a and b), carotenoid content, anthocyanin and amylases (α and β) activities were found to be altered. Significant alterations in percentage of seed germination (P < 0.001) and time to 50% germination (P < 0.001) were observed in the irradiated seeds compared with the un‐irradiated controls. In conclusion, the results of the present study demonstrated that low dose (5–30 J cm^?2) of He–Ne laser irradiation enhanced the germination process and altered growth, by positively influencing physiological and biochemical parameters of the brinjal seedlings compared with un‐irradiated control under in vitro conditions.     

Large grained and high charge carrier lifetime CH3NH3PbI3 thin-films: implications for perovskite solar cells

Spin coated perovskite thin films are known to have an issue of pinholes & poor morphology control which lead to poor device-to-device repeatability, that is an impediment to scale-up. In this work, Methylamine vapor annealing process is demonstrated which consistently leads to high-quality perovskite thin-films with an average grain-size of 10–15 μm. The improvement in film morphology enables improvement in effective carrier recombination lifetime, from 21 μs in as-deposited films to 54 μs in vapor-annealed films. The annealed films with large-grains are also more stable in ambient conditions. Devices made on annealed perovskite films are very consistent, with a standard deviation of only 0.7%. Methylamine vapor annealing process is a promising method of depositing large-grain CH₃NH₃PbI₃ films with high recombination lifetime and the devices with improved performance.