  Semi-transparent Solar Cells (ST-SCs) has emerged as one of the most
prominent energy harvesting technology that combines the benefits of light
transparency and light-to-electricity conversion. The biggest opportunities for
such technologies lie in their integration as windows and skylights within
energy-sustainable buildings or combining them with other solar cell
technologies in tandem configuration. The performance of ST-SCs is mainly
determined by the trade-off between the competing parameters of the capability
to convert the incident light into electricity while allowing some parts to
transmit providing transparency through the device. Depending on the target
application, the selection of ST-SCs is a tricky affair as some devices might
offer high efficiency but compromises transparency and vice-versa. On the other
way around, this is again not helped by the fact that due to advancements in
materials engineering, processing, and characterization, a vastly different
combination of efficiency and transparency has been reported by research
groups. So, in order to quantify the performance of ST-SCs, we proposed, a
figure-of-merit (FoM) which can be used as a tool that can help in analysing
and comparing the performance among various ST-SCs. The defined FoM focuses on
the power conversion efficiency of the device, bifaciality factor,
transmittance in the desired region, and that corresponding to 550 nm
wavelength. Additionally, in this work, we have been shown how the proposed FoM
can be correlated for tandem and building-integrated photovoltaics
applications. Based on these resultant parameters, FoM is calculated and
compared for different device architectures available in the literature. The
proposed FoM shall serve as a meaningful guiding path to the researchers for
the development of advanced ST-SCs.
