A Study of the Electron Regeneration Efficiency of Solar Cells Fabricated Using CMC/PVA-, Alginate-, and Xanthan-based Electrolytes

Abstract

A photovoltaic (PV) mechanism consists of three important steps, i.e., (i) electron excitation upon absorption of photon with energy higher than the bandgap of fluorophore, (ii) excited-state electron injection fro m the fluorophore to the photoelectrode, and (iii) electron regeneration fro m the electrolyte to the fluorophore. An efficient electron regeneration could be achieved upon fulfillment of the requirements of energy align ment, i.e., lo west unoccupied molecular orb ital of fluorophore (LUM O fluorophore ) > redo x potential of electrolyte > highest occupied molecu lar orbital of fluorophore (HOMO fluorophore ). This study investigated the electron regeneration efficiency of excitonic solar cells fabricated using three polymer-based electrolytes, i.e., (i) 60% carbo xy methyl cellulose (CM C) blended with 40% polyvinyl alcohol (PVA ), (ii) alginate, and (iii) xanthan. The redo x potentials of the electro lytes (E o ) were calculated using quantum chemical calculat ions under the framework of density functional theory. The compatibility of fluorophore and electrolyte was analyzed in terms of the energy level align ment. The cells fabricated using the three polymer-based electrolytes were analyzed, with the CMC/PVA -based cell yielding the highest efficiency, η, of 1.39% under the illu mination of the sun. The low η of the cells can be attributed to the incompatible E o of the electrolytes, which exh ibited a higher energy level than the LUM O fluorophore . The alginate-and xanthan-based cells exh ibited inferior PV propert ies (i.e., open circuit voltage, short circuit current, fill factor, and η) to that of the CMC/PVA-based cell. This finding can be attributed to the increment of energy offset between E o and HOMO fluorophore . AbstractSebuah Studi Tentang Efisiensi Regenerasi Elektron Sel Surya yang Di buat Menggunakan CMC/PVA-, Alginat-, dan Elektrolit Berbasis Xanthan. Mekanis ma fotovoltaik (PV) terdiri daripada tiga langkah penting iaitu (i) pengujaan elektron apabila penyerapan foton dengan tenaga yang lebih tinggi daripada jurang jalur fluorofora, (ii) suntikan elektron yang teruja dari fluorofora kepada fotoelektrod, dan (iii) pengenerasian semula elektron daripada elektro lit ke fluorofora. Pengenerasian semula elektron yang efisien dapat dicapai apabila memenuhi keperluan penjajaran tenaga iaitu, LUM O fluorofora > potensi redoks elekt rolit > HOMO fluorofore . Kertas kerja in i membentangkan kajian kecekapan pengenerasian semula sel suria eksitonik yang dibentuk menggunakan tiga elektrolit berasaskan polimer iaitu, (i) 60% karboksimet il selu losa (CMC) yang dicampur dengan 40% alkohol poliv inil (PVA), (ii) alginate dan (iii) xanthan. Potensi redoks elektrolit (E o ) dihitung menggunakan pengiraan kimia kuantum di bawah rangka density functional theory (DFT). Analisis fluorofora dan elektrolit adalah sesuai berdasarkan kepada penjajaran tahap tenaga. Setiap sel yang dibina dengan menggunakan tiga jenis elektrolit telah dianalisis; CM C/PVA menghasilkan kecekapan tertinggi, 1.39% di bawah pe...