Structural and optical properties in manganese doping-driven Bi-based perovskite microcrystal

In optoelectronic applications, perovskite based on caesium bismuth bromide presents a competitive, non-toxic substitute to overcome the environmental challenges associated with lead halide perovskites. Cs 3 Bi 2 Br 9 is of interest owing to its high ambient and thermal stabilities, optoelectronic properties, and being less polluting to the environment. However, they have higher band gaps and lower electrical merits than their Pb counterparts. This disparity is primarily due to their higher electron-hole pair binding energy, low absorption coefficient, and poor film morphology. We synthesize Cs 3 Bi 2 Br 9 microcrystals and, as a proof of concept, integrated them in an n-i-p type solar cell using pristine and Mn(II) doped Cs 3 Bi 2 Br 9 as an absorber. Temperature-dependent XRD and UV-Vis absorption measurements revealed that the deposited thin film maintains phase stability and optical integrity up to about 200°C. X-ray diffraction patterns suggest the effective integration of Mn with minimum structural deformation and enhanced crystallinity. Cs 3 Bi 2 Br 9 is potentially a thermally stable, non-toxic semiconductor for next-generation optoelectronics. Device architect of Cs 3 Bi 2 Br 9 based solar cells and J-V curves with device image in inset. • We synthesized Cs 3 Bi 2 Br 9 microcrystals and studied the effect of Mn doping • We used pristine and Mn(II) doped Cs 3 Bi 2 Br 9 as an absorber for solar cells fabrication • The Cs 3 Bi 2 Br 9 thin film maintains phase stability and optical integrity up to about 200 °C • Environmental benign semiconductors stable upto 200 °C