Synergistic energy system [Sm3+-Eu3+-Tm3+]:CsPbI2.4Br0.6 designing and thermal optimization for photovoltaic and electrical applications

Current work, for the first time elucidates the fabrication and energy applications of the novel perovskite hetero-system formed by the ternary lanthanide doping of CsPbI2.4Br0.6 leading to formation of [Sm3+-Eu3+-Tm3+]:CsPbI2.4Br0.6 (SET:CPVSK). SET:PVSK was tailored for the band gap spanning over the range of 1.59–1.66 eV over the course of 28 days, exhibiting excellent stability. With the cubic crystalline geometry, the spin coated thin films expressed maximum coverage and profound binding to substrate. As a perovskite light absorber, SET:CVSK based solar cell gained an efficiency of 17 % with the 68.92 % of fill factor and an expanded open circuit voltage (Voc) of 1.08 V. As an electro-catalyst, SET:CPVSK expressed moderate oxygen generation. While it demonstrated magnanimous pure hydrogen generation showing impressively minimal overpotential and Tafel slope value of 142 mV and 122.7 mV dec−1, respectively. With an extended service life in the electrolyte medium, SET:CPVSK adorned nickel foam electrode was marked by superior unit capacity of 661.24 mAH g−1 while the equivalent series resistance (Rs) i.e. 0.67 Ω, which shows the minimal resistance and facilitated diffusion of ions.