Numerical Analysis of the Impact of Absorber Layer Defect Density on the Performance of Cs₂AgBiBr₆-Based Solar Cells

In light of contemporary environmental issues, the introduction of lead-free alternatives, such as Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> perovskites, has gained significance. This is because lead-based perovskite solar cells (PSCs) pose problems due to their poisonous nature and lack of stability. The Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> compounds exhibit outstanding solar harvesting capabilities due to their high light absorption efficiency. Despite persistent worries regarding lead exposure and long-term durability, Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> PSCs are attracting interest as a promising solar energy alternative. The primary objective of this study is to examine the photovoltaic (PV) qualities. This study demonstrates significant advancements in the field of photovoltaics, particularly focusing on the development of PSCs using Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf>. The study examines the range of bulk defect density (Nt) values, specifically ranging from 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> to 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">17</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup>. It offers comprehensive analysis by utilising the properties of PV technology. The work employed the SCAPS-1D simulation programme to model the proposed design of PSC based on Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> and enhance its properties. The results highlight the substantial influence of the absorption layer Nt on the PV characteristics, underscoring the importance of precise thickness control to improve the performance of PSCs. The research demonstrates that Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf>-based PSCs have a substantial capability to serve as a practical and cost-effective method for producing renewable energy. The research indicates that the PV characteristics achieve their maximum levels whenever the defects in PV cells based on Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> are restricted. The cells exhibit a substantial enhancement in performance when the defect concentration reaches 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup>. The fill factor (FF) achieves its highest value at 90.6%, the short-circuit current (J<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</inf>) is 21.44 mA/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, and the open-circuit voltage (V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</inf>) is 1.39V. The power conversion efficiency (PCE) is 27.1% in conditions of low defect density. The findings are meticulously contextualised within the existing body of literature to emphasise the advancements of the research on safe-to-consume inorganic perovskite sources of energy. The objective of this endeavour is to achieve sustainable progress in PV technology.