Decoding the charge carrier dynamics in triple cation-based perovskite solar cells. Issue 24 (11th November 2021)

• Record Type: Journal Article
• Authors: Khan, Mohd Taukeer; Hemasiri, Naveen Harindu; Kazim, Samrana; Ahmad, Shahzada
• Is Part Of: Sustainable energy & fuels. Volume 5:Issue 24(2021)
• Page Start: 6352
• Page End: 6360
• Publication Date: 2021-11-11
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/d1se01398j
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : By deciphering the charge carrier dynamics in perovskite solar cells (PSCs) we noted deep (254 meV) and shallow (91 meV) trap states observed at low and high frequencies respectively, corresponds to ionic migration/electronic trapping. Abstract : Deciphering the charge carrier dynamics in perovskite solar cells (PSCs) and electrical merits is essential to further improve the performance and operational stability. We investigated the charge carrier dynamics in triple cation-based PSCs through temperature dependent electrochemical impedance spectroscopy, thermal admittance spectroscopy, and space charge limited current (SCLC). The temperature dependent capacitance versus frequency ( C – f ) spectra reveal two kinds of activation process, one at low frequency and high temperature (>260 K), and the other at high frequency and low temperature (<260 K). The evaluated activation energy ( E A ) at a high temperature from all three experiments was found to be in the range of 0.255–0.266 eV, which corresponds to the activation of the migration of halide anions, while the low-temperature activation process stems from the trapping/de-trapping of electronic charges from shallow traps. The trap density of states in triple cation-based perovskites (10 15 eV −1 cm −3 ) was evaluated to be over two to six orders of magnitude lower than that of typically used single cation-based perovskites, while the charge carrier mobility (5.76 × 10 −3 cm 2 V −1 s −1 ) evaluated from the SCLC technique was nearly an order of magnitude higher than that of single cation perovskites.