Structural, Optoelectronic and Electrochemical behavior of the mechanochemically synthesized CsPb1-xNaxBr3 (x=0 to 0.15)

Mechanochemical synthesis of CsPb1-xNaxBr3 (x = 0-0.15) compositions were carried out and their structural, optoelectronic, and electrochemical characteristics were explored deeply. All compositions were stabilized in the orthorhombic phase and structural parameters extracted from the Rietveld refinement indicates complex substitution dynamics involving both interstitial and Pb vacant sites. The influence of Na incorporation on the optoelectronic characteristics (band gap and absorption wavelength) were observed to be almost invariable across the compositions. A three-fold increase in photoluminescence intensity (with peak around 533-537 nm) was observed for Na (x = 0.15) in comparison to the parent phase. The major highlights of the electrochemical characteristics are increased specific capacitance from 19 mu F/mg (x = 0) to 38 mu F/mg (x = 0.15), better current density (similar to 2 mA/cm2), and the extended electrochemical window for x = 0.15 composition.