Tuning of the Contact Properties for High-Efficiency Si/PEDOT:PSS Heterojunction Solar Cells

Abstract

Heterojunction solar cells (HSCs) featuring half and full contact of poly (3,4-ethylenedioxythiophene):polystyrene (PE-DOT:PSS) with pyramid-textured silicon (Si) were thoroughly compared via simulations and experiments, and the following conclusions have been reached: (1) The insufficient electrical passivation inherent to the half contact results in enormous decline in short-circuit current density (J sc ) and open-circuit voltage (V oc ). ( 2) For the full-contact HSCs, J sc is mainly dependent on the recombination at the rear interface. With tuning of the contact properties from both sides, calculated (experimental) efficiencies of 14.46%/16.89% (13.94%/16.21%) for the half-/full-contact HSCs were finally obtained. A superior power conversion efficiency (PCE) over 21% is further predicted by considering more optimal contact resistance as well as doping concentration of Si. Our findings clarify why textured-Si/PEDOT:PSS HSCs show V oc and PCE that are inferior to those of planar counterparts in previous reports and further suggest a pathway to fully explore the efficiency potential of Si/PEDOT:PSS hybrid solar cells.

Tantalum Nitride Electron‐Selective Contact for Crystalline Silicon Solar Cells

“…[28][29][30][31][32] Metal-oxide, fluoride, and polymerbased DF-CSCs are easy to deposit at an acceptable cost (e.g., thermal evaporation, spin coating, or atomic layer deposition, ALD); however, most of them suffer from a poor stability, either chemically or thermally, [11,16,18,23,24,33] which limits their industrial applications. When the metal is in direct contact with the silicon surfaces, very large densities of electronic states at the interface can be introduced into 8-hydroxyquinolinolato-lithium (Liq), perylene diimide, have also been developed.…”

Superacid-Treated Silicon Surfaces: Extending the Limit of Carrier Lifetime for Photovoltaic Applications

“…The most promising organic film developed thus far is poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which passivates the silicon surface and functions as a hole conducting layer [10]. Applications to the front textured surface of silicon solar cells have recently led to Yang et al demonstrating open-circuit voltages (V oc ) of 634 mV and S of 100 cm/s [11] while Zhang et al have reported the same V oc of 634 mV applying the PEDOT:PSS passivating hole contact layer to the rear side of silicon-based solar cells [12]. In contrast, Schmidt et al have demonstrated better electronic properties for rear-passivated PEDOT:PSS solar cells, where an emitter saturation current density (J oe ) of 80 fA/cm 2 and an implied open-circuit voltage (iV oc ) of 690 mV have been reported [13], [14].…”

Heterojunction Hybrid Solar Cells by Formation of Conformal Contacts between PEDOT:PSS and Periodic Silicon Nanopyramid Arrays

“…This change in morphology resulted in a great decrease in surface recombination velocity (from 300 to 100 cm s −1 ) at the interface of PEDOT:PSS/Si‐pyramids, leading to a significant improvement on junction quality. These studies further prove that the formation of a conformal contact is essential to both better optical absorption and carrier collection (with full‐area electrical passivation) . However, the aforementioned textures with random configurations may cause the problem of nonuniform coating of PEDOT:PSS, resulting in large shunt resistance and deteriorated open‐circuit voltage for the resulting solar devices.…”