Abstract:
Antimony selenide (Sb2Se3) is considered a promising candidate utilized as an absorber in thin film solar cell
(TFSC) technology thanks to its non-toxic and earth-abundant nature besides its reported high absorption co-
efficient. To enhance the power conversion efficiency (PCE) of Sb2Se3 solar cells, we report some design sug-
gestions by applying device simulation. The numerical model is firstly validated by calibration of simulation
results vs those from an experimental Sb2Se3 solar cell structure composed of FTO/CdS/Sb2Se3/Au where CdS
serves as an electron transport layer (ETL). Then, the cell is modified to include an embedded p-n homojunction.
In contrast to the conventional heterostructure design, a homojunction structure has crucial benefits in terms of
both electronic and optoelectronic characteristics such as the extra produced built-in electric field which can
increase the transport of photogenerated carriers. Three device configurations are presented and compared. The
first and the second cases are when using CdS and ZnOS as ETLs. Utilizing ZnOS ternary compound is found to be
more beneficial as its conduction band offset with the absorber layer could be tuned to attain a proper cliff-like
band alignment. The third case is when considering homojunction design free from all carrier transport layers.
Possible paths for device optimization are investigated to boost the efficiency in a try to overcome the efficiency
bottleneck encountered in the Sb2Se3-based quasi homojunction solar cells. All simulations, performed in this
study, are done by SCAPS device simulation software under standard AM1.5G one Sun illumination
