Baran Group Meeting

Terry Lou Solid-state (ss) DSSC - Incomplete penetration into nanoporous TiO2 Dye-Sensitized Solar Cells - Poor electronic contact with dye - Thin layer of TiO 2 is needed, hence reduce light absorption - Fast charge recombination between e in TiO 2 and h* in HTM Low conductivity of HTMs Hole transporting material (HTM) - - Conducting polymer, e.g. PEDOT Hole-conducting molecules, e.g. spiro-MeOTAD Quasi-solid-state electrolyte • • Polymer swollen with liquid electrolyte Overcome volatility & leakage problem p-Type semiconductor, e.g. CsSnl 2.95 F0.05 Dried out electrolyte ("Zombie cells") DSSCs normally died upon evaporation of redox electrolyte MeO MeO Retention of performance of dried-out cells was observed using [Cu(dmp)2]2+/+ (Gerrit, 2015) OMe OMe PEDOT OMe OMe Spiro-MeOTAD ⚫ Dried out [Cu(tmby)2]2+/+ gave the highest ssDSSC efficiency of 11.7% (Zhang, 2018) "electrolyte solvent was evaporated in a dry box by keeping the holes on the counter electrode unsealed for a period of more than one week" -OMe -OMe Counter electrode Baran Group Meeting Jun 5, 2021 TCO-coated glass (or conducting polymer) as substrate Commonly spray-coated with Pt (as catalyst and high conductivity) Carbon nanotube, graphene, C 60, PEDOT were also used p-Type DCCS Best n < 1% Rather unexplored NiO commonly used as electrode (lower VB is preferred) counter electrode electrolyte dye D*/D* (a) (b) hv NiO film CB -1 Tandem pn-DSSC Theoretical limit of n = 43% p-DSSC as photocathode Photocurrent from two electrodes have to be matched e cb e LUMO e hv 0 EI/13 VB 1 I/I3* D/D+ 2 E load V vs NHE TiO2 HOMO N719 1/13 e LUMO hv HOMO Dye 3 vb NiO (Nattestad, 2010) n = 2.4%; 8

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