Low Lead All-Inorganic Hybrid Perovskite: A Study of Interface Defects using SCAPS-1D

Hybrid perovskites are promising materials for photovoltaic applications due to their long diffusion length, high absorption coefficient, longer carrier lifetime, and adjustable bandgaps. However, the toxic nature of lead in hybrid perovskites is still a concern for the environment. In this work, a low-lead, all-inorganic perovskite material (CsP$\mathrm{b}_{0.625} Z \mathrm{n}_{0.375}$IC1
2
) is proposed as the absorber layer. The addition of zinc reduces lead content, and all-inorganic materials have better stability against temperature and moisture variations. TiO
2
is selected as the electron transport layer (ETL) and Spiro-MeOTAD as the hole transport layer (HTL) to efficiently collect the charge carriers at electrodes. The proposed design (TiO
2
/CsP$\mathrm{b}_{0.625} Z \mathrm{n}_{0.375}$IC1 2/SpiroMeOTAD) has been verified in the SCAPS-ID simulator under the influence of interface defect variation. Results show a decrease in current density and quantum efficiency with an increase in interface defect density at the ETL/absorber layer interface. It is observed that the current density decreases from 33.02 mA/cm
²
to 29.97 mA/cm
²
with an interface defect density of 1 x10
¹⁰
c$\mathrm{m}^{-2}$ and 1 x10
^1S
c$\mathrm{m}^{-2}$, respectively. However, for the absorber layer/HTL interface, the current density remains constant at 33.02 mA/cm
²
on variation of defect density from 1 x10
¹⁰
c$\mathrm{m}^{-2}$ to 1 x10
^1S
c$\mathrm{m}^{-2}$.