Unlocking Potential with Semcarbazide Hydrochloride (SEM-HCl)
In the pursuit of efficient and stable lead-free perovskite solar cells, researchers at Nanjing University of Posts & Telecommunications, led by Prof. Ligang Xu, have made a significant breakthrough. The use of tin perovskites has garnered attention, but challenges arise from Sn vacancies and undercoordinated Sn ions, leading to deep-level traps, hampering device efficiency and stability.
Innovative Approach: SEM-HCl Integration
The research introduces semicarbazide hydrochloride (SEM-HCl) into the tin perovskite precursor, revolutionizing the fabrication process. SEM-HCl not only reduces the quantity of uncoordinated Sn2+ on the surface but also modulates intrinsic Sn deep-level defects. This dual action enhances the quality of perovskite films, ultimately boosting device performance.
Coordination Interactions for Enhanced Stability
SEM-HCl’s O=C-N functional group forms coordination interactions with charge defects in tin perovskites. This interaction intensifies the electron cloud density surrounding defects and increases vacancy formation energies. Critically, this approach reduces the deep-level trap state density, stemming from undercoordinated Sn2+ ions and Sn4+ oxidation, reducing nonradiative recombination.
Outstanding Results: Championing Efficiency and Stability
The Tin-Based Perovskite Solar Cells (TPSCs) developed through this method achieve a remarkable champion Power Conversion Efficiency (PCE) nearing 11%. Equally noteworthy is the exceptional stability demonstrated, with unencapsulated devices maintaining nearly 100% of their initial efficiencies after 100 hours of operation under AM1.5 illumination conditions.
Published Findings: A Step Forward in Solar Technology
The research, titled “Suppression of deep-level traps via semicarbazide hydrochloride additives for high-performance tin-based perovskite solar cells,” was published on December 29, 2023, in Frontiers of Optoelectronics. This breakthrough promises a brighter future for lead-free perovskite solar technology, marking a significant stride in renewable energy innovation.
Source：miragenews.com
