TY - INPR A1 - Mosavi, Amir A1 - Moeini, Iman A1 - Ahmadpour, Mohammad A1 - Alharbi, Naif A1 - E. Gorji, Nima T1 - Modeling the time-dependent characteristics of perovskite solar cells N2 - We proposed two different time-dependent modeling approaches for variation of device characteristics of perovskite solar cells under stress conditions. The first approach follows Sah-Noyce-Shockley (SNS) model based on Shockley–Read–Hall recombination/generation across the depletion width of pn junction and the second approach is based on thermionic emission model for Schottky diodes. The connecting point of these approaches to time variation is the time-dependent defect generation in depletion width (W) of the junction. We have fitted the two models with experimental data reported in the literature to perovskite solar cell and found out that each model has a superior explanation for degradation of device metrics e.g. current density and efficiency by time under stress conditions. Nevertheless, the Sah-Noyce-Shockley model is more reliable than thermionic emission at least for solar cells. KW - Solarzelle KW - Solar KW - Solar cells KW - Modeling KW - Time-dependent KW - Defect generation KW - Perovskite Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20180907-37573 N1 - Published in final form at https://doi.org/10.1016/j.solener.2018.05.082. ER - TY - JOUR A1 - Jilte, Ravindra A1 - Ahmadi, Mohammad Hossein A1 - Kumar, Ravinder A1 - Kalamkar, Vilas A1 - Mosavi, Amir T1 - Cooling Performance of a Novel Circulatory Flow Concentric Multi-Channel Heat Sink with Nanofluids JF - Nanomaterials N2 - Heat rejection from electronic devices such as processors necessitates a high heat removal rate. The present study focuses on liquid-cooled novel heat sink geometry made from four channels (width 4 mm and depth 3.5 mm) configured in a concentric shape with alternate flow passages (slot of 3 mm gap). In this study, the cooling performance of the heat sink was tested under simulated controlled conditions.The lower bottom surface of the heat sink was heated at a constant heat flux condition based on dissipated power of 50 W and 70 W. The computations were carried out for different volume fractions of nanoparticles, namely 0.5% to 5%, and water as base fluid at a flow rate of 30 to 180 mL/min. The results showed a higher rate of heat rejection from the nanofluid cooled heat sink compared with water. The enhancement in performance was analyzed with the help of a temperature difference of nanofluid outlet temperature and water outlet temperature under similar operating conditions. The enhancement was ~2% for 0.5% volume fraction nanofluids and ~17% for a 5% volume fraction. KW - Nanostrukturiertes Material KW - Kühlkörper KW - Nasskühlung KW - nanofluid KW - Nanomaterials KW - Machine learning KW - heat sink Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200401-41241 UR - https://www.mdpi.com/2079-4991/10/4/647 VL - 2020 IS - Volume 10, Issue 4, 647 PB - MDPI CY - Basel ER -