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lithium-doping
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Enhanced Electronic Properties in Mesoporous TiO2 Via Passivation Treatment in Perovskite Solar Cells
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Mohammad Reza (Supervisor)
Abstract
Perovskite solar cells are the new generation of solar cells, and are mainly introduced in two types of structures.1) planer and 2) mesoscopic structure. The difference between these two structures derives from the absence of mesoporous layer in the planer structures. The mesoporous layer acts as an electron transporting layer, and is mainly a titanium dioxide semiconductor. To apply the mesoporous layer, the preparation of the TiO2 paste is needed.The synthesis of titanium dioxide nanopowder for the preparation of TiO2 paste requires high temperature heat treatment and is not desirable in terms of energy consumption.Another weakness of this layer is the presence of surface defects, which...
Transesterification of canola oil and methanol by lithium impregnated CaO–La2O3 mixed oxide for biodiesel synthesis
, Article Journal of Industrial and Engineering Chemistry ; Volume 47 , 2017 , Pages 399-404 ; 1226086X (ISSN) ; Kazemeini, M ; Larimi, A. S ; Khorasheh, F ; Sharif University of Technology
Abstract
CaO–La2O3 mixed oxides were synthesized by co-precipitation coupled with Li doping through wet impregnation. These were used as catalysts for transesterification of canola oil and methanol toward biodiesel production. To determine the structure and morphology of the prepared catalysts, they were characterized by the XRD, FESEM, BET, and basic strength measurements. Under optimum reaction conditions of methanol/oil molar ratio of 15:1, 5 wt% catalyst at 65 °C, 96.3% conversion was obtained in 2.5 h of reaction duration. Moreover, the catalyst demonstrated a rather high stability where reuse of up to five cycles without significant loss of performance observed. © 2016 The Korean Society of...
Fabrication and Characterization of Inverted Perovskite Solar Cells Using Nickel Oxide as Hole Transporting Layer
, Ph.D. Dissertation Sharif University of Technology ; Taghavinia, Nima (Supervisor)
Abstract
In this research, we study and optimize the inverted perovskite solar cells (PSCs) using nano layers of NiOx and Li:NiOx as hole transporting layers (HTLs) and nano layers of PC70BM and C60 as electron transporting layers (ETLs). We fabricated inverted PSCs with three different HTLs, namely MoOx, PEDOT:PSS and NiOx, using vapor assisted solution processed (VASP) method for making MAPbI3 perovskite which yielded a power conversion efficiency (PCE) of 1%, 1.93% and 3.65%, respectively. Solution-processed deposition method, high transparency (˃90%) and high band gap (3.9 eV) are the most advantages to use NiOx as HTL in current research. Using lithium as dopant to the NiOx increases the...
The effect of lithium doping in solution-processed nickel oxide films for perovskite solar cells
, Article ChemPhysChem ; Volume 20, Issue 24 , 2019 , Pages 3322-3327 ; 14394235 (ISSN) ; Sveinbjornsson, K ; Boschloo, G ; Taghavinia, N ; Sharif University of Technology
Wiley-VCH Verlag
2019
Abstract
The effect of substitutional Li doping into NiOx hole transporting layer (HTL) for use in inverted perovskite solar cells was systematically studied. Li doped NiOx thin films with preferential crystal growth along the (111) plane were deposited using a simple solution-based process. Mott-Schottky analysis showed that hole carrier concentration (NA) is doubled by Li doping. Utilizing 4 % Li in NiOx improved the power conversion efficiency (PCE) of solar devices from 9.0 % to 12.6 %. Photoluminescence quenching investigations demonstrate better hole capturing properties of Li:NiOx compared to that of NiOx, leading to higher current densities by Li doping. The electrical conductivity of NiOx is...