Multidentate anchoring through additive engineering for highly efficient Sb_(2)S_(3)planar thin film solar cells

摘要

Sb_(2)S_(3)is a promising candidate for the flexible solar cells or the top subcells in tandem solar cells due to its wide-bandgap,less toxic,acceptable cost and progressive power conversion efficiency(PCE).However,the poor quality and high trap states of Sb_(2)S_(3)films limit the device performance further enhancement.Herein,we adopt a multidentate ionic liquid,tetramethylammonium hexafluorophosphate([TMA][PF_(6)])as a novel additive to address this issue.The octahedral[PF_(6)]~-contains six different oriented fluorine atoms with the lone pair electrons,which could coordinate with Sb atoms due to the multidentate anchoring.Thus,the high-quality Sb_(2)S_(3)film with low trap states has been achieved.Moreover,the Fermi level of the Sb_(2)S_(3)film has been upshifted,thereby showing an effective charge transfer.As a result,all photovoltaic parameters of the optimized Sb_(2)S_(3)devices are obviously enhanced,boosting the final PCE from 4.43(control device)to 6.83%.Our study about the multidentate anchoring is manifested to be an effective method to enhance the Sb_(2)S_(3)device performance.