Browsing by Author "Sajid, Sajid"

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Citation - WoS: 17
Citation - Scopus: 18
Antisolvent-Fumigated Grain Growth of Active Layer for Efficient Perovskite Solar Cells
(Pergamon-elsevier Science Ltd, 2021) Sajid, Sajid; Khan, Suliman; Khan, Ayub; Khan, Danish; Issakhov, Alibek; Park, Jongee; Metallurgical and Materials Engineering
High efficiency of perovskite solar cell can be obtained through various approaches, including materials and interface engineering, device modification and fabrication techniques. In all approaches, the quality of the perovskite layer has a significant impact on the efficiency of the perovskite solar cell. Antisolvent dripping is widely used in almost all fabrication methodologies to achieve a high-quality perovskite layer. However, in the conventional antisolvent dripping, there are several factors (antisolvent volume, time and point of dripping, etc.) to be strictly followed. Due to these difficult and critical tricks, researchers often get perovskite layers with pinholes, small grains, and wide grain boundaries that deteriorate the performance of the perovskite solar cells. In order to produce perovskite films with large-scale grains, narrow boundaries and smooth surface morphology, a sealed antisolvent-fumigated process is implemented. There is no need to make any substantial efforts to achieve optimal conditions for the fabrication of high-quality perovskite layers using the antisolvent-fumigated strategy. Consequently, the efficiency of perovskite solar cell improves dramatically from 18.65% to 21.45%. Our findings present a new and convenient method for fabricating highly efficient perovskite solar cells.
Citation - WoS: 4
Citation - Scopus: 4
Diethanolamine Modified Perovskite-Substrate Interface for Realizing Efficient Esl-Free Pscs
(Mdpi, 2023) Sajid, Sajid; Alzahmi, Salem; Wei, Dong; Ben Salem, Imen; Park, Jongee; Obaidat, Ihab M.; Metallurgical and Materials Engineering
Simplifying device layout, particularly avoiding the complex fabrication steps and multiple high-temperature treatment requirements for electron-selective layers (ESLs) have made ESL-free perovskite solar cells (PSCs) attractive. However, the poor perovskite/substrate interface and inadequate quality of solution-processed perovskite thin films induce inefficient interfacial-charge extraction, limiting the power conversion efficiency (PCEs) of ESL-free PSCs. A highly compact and homogenous perovskite thin film with large grains was formed here by inserting an interfacial monolayer of diethanolamine (DEA) molecules between the perovskite and ITO substrate. In addition, the DEA created a favorable dipole layer at the interface of perovskite and ITO substrate by molecular adsorption, which suppressed charge recombination. Comparatively, PSCs based on DEA-treated ITO substrates delivered PCEs of up to 20.77%, one of the highest among ESL-free PSCs. Additionally, this technique successfully elongates the lifespan of ESL-free PSCs as 80% of the initial PCE was maintained after 550 h under AM 1.5 G irradiation at ambient temperature.
Citation - WoS: 20
Citation - Scopus: 20
Identifying the Potentials for Charge Transport Layers Free N-P Homojunction-Based Perovskite Solar Cells
(Pergamon-elsevier Science Ltd, 2022) Khan, Danish; Sajid, Sajid; Khan, Suliman; Park, Jongee; Ullah, Ihsan; Metallurgical and Materials Engineering
Perovskite solar cells (PSCs) with no charge transport layers (CTLs) could be one of the major device architectures for the production of simple and low-cost devices. However, CTLs-free PSCs based on n-p homojunction have yet to show high power conversion efficiency (PCE), which is most likely due to inadequate light-and charge-management in the p-type perovskite. The device operation is examined using Solar Cell Capacitance Simulator (SCAPS)-software, and a novel n-p homojunction design is proposed to attempt efficient CTLs-free PSCs. Several aspects of p-type layer that can affect device performance, such as acceptor density, photon harvesting capability, defects density, and resistances to the transport of charge-carriers are scrutinized and adjusted. Furthermore, the effects of different work-functions of metal electrodes are examined. A suitable acceptor concentration is required for oriented charge transport. It is determined that a p-type perovskite with a thickness of 0.3 mu m is advantageous for high performance. A metal electrode with a high work-function is essential for efficient device. Consequently, a PCE of 15.60% is obtained with an optimal defect density of E15 cm(-3), indicating that n-p homojunction-based CTLs-free PSCs are promising since they simplify the device design and fabrication process while retaining an acceptable PCE.
Citation - WoS: 16
Citation - Scopus: 17
Inorganic Hole Transport Materials in Perovskite Solar Cells Are Catching Up
(Elsevier Sci Ltd, 2023) Sajid, Sajid; Alzahmi, Salem; Ben Salem, Imen; Park, Jongee; Obaidat, Ihab M.; Metallurgical and Materials Engineering
More research is required to further optimize device efficiency, stability, and reduce the materials cost as perovskite solar cells (PSCs) approach to industrialization. Modulating the optoelectronic features and chemical coupling of the hole transport materials (HTMs) remains a prominent field of study in PSCs due to the significant impact these materials have on the device performance and stability. In order to speed up the commercialization of these cells, it is also important to use cost-effective HTMs in PSCs. InorganicHTMs are superior to other types of HTMs in terms of their advantages in boosting device performance and producing PSCs at a reasonable cost, in addition to their superior charge transport capabilities, desired energy levels, and intrinsic thermal and chemical stability. A detailed overview of inorganicHTMs, including metal oxides, cyanates, phthalocyanines, chalcogenides, nitrides, and carbides, is presented in this review. After briefly discussing the primary physical and optoelectronic characteristics of inorganic-HTMs, the critical functions of the above-mentioned materials as HTMs in PSCs are addressed. This review concludes by offering suggestions for future research that could considerably boost the performance of the PSCs with cost-effective inorganic-HTMs.
Citation - WoS: 11
Citation - Scopus: 13
Lead-Free Perovskite Homojunction-Based Htm-Free Perovskite Solar Cells: Theoretical and Experimental Viewpoints
(Mdpi, 2023) Sajid, Sajid; Alzahmi, Salem; Salem, Imen Ben; Park, Jongee; Obaidat, Ihab M.; Metallurgical and Materials Engineering
Simplifying the design of lead-free perovskite solar cells (PSCs) has drawn a lot of interest due to their low manufacturing cost and relative non-toxic nature. Focus has been placed mostly on reducing the toxic lead element and eliminating the requirement for expensive hole transport materials (HTMs). However, in terms of power conversion efficiency (PCE), the PSCs using all charge transport materials surpass the environmentally beneficial HTM-free PSCs. The low PCEs of the lead-free HTM-free PSCs could be linked to poorer hole transport and extraction as well as lower light harvesting. In this context, a lead-free perovskite homojunction-based HTM-free PSC was investigated, and the performance was then assessed using a Solar Cell Capacitance Simulator (SCAPS). A two-step method was employed to fabricate lead-free perovskite homojunction-based HTM-free PSCs in order to validate the simulation results. The simulation results show that high hole mobility and a narrow band gap of cesium tin iodide (CsSnI3) boosted the hole collection and absorption spectrum, respectively. Additionally, the homojunction's built-in electric field, which was identified using SCAPS simulations, promoted the directed transport of the photo-induced charges, lowering carrier recombination losses. Homojunction-based HTM-free PSCs having a CsSnI3 layer with a thickness of 100 nm, defect density of 10(15) cm(-3), and interface defect density of 10(18) cm(-3) were found to be capable of delivering high PCEs under a working temperature of 300 K. When compared to formamidinium tin iodide (FASnI(3))-based devices, the open-circuit voltage (V-oc), short-circuit density (J(sc)), fill factor (FF), and PCE of FASnI(3)/CsSnI3 homojunction-based HTM-free PSCs were all improved from 0.66 to 0.78 V, 26.07 to 27.65 mA cm(-2), 76.37 to 79.74%, and 14.62 to 19.03%, respectively. In comparison to a FASnI(3)-based device (PCE = 8.94%), an experimentally fabricated device using homojunction of FASnI(3)/CsSnI3 performs better with V-oc of 0.84 V, J(sc) of 22.06 mA cm(-2), FF of 63.50%, and PCE of 11.77%. Moreover, FASnI(3)/CsSnI3-based PSC is more stable over time than its FASnI(3)-based counterpart, preserving 89% of its initial PCE. These findings provide promising guidelines for developing highly efficient and environmentally friendly HTM-free PSCs based on perovskite homojunction.