On the kinetics of charge transfer between an illuminated CdSe electrode and polysulphide electrolyte

Understanding the Role of the Sulfide Redox Couple (S2–/Sn2–) in Quantum Dot-Sensitized Solar Cells

“…9 Sulfide electrolytes are effective in scavenging the photogenerated holes and can tackle the issues related to anodic photocorrosion. 10,11 For example, the sulfide/ polysulfide redox couple is effective in scavenging the holes of CdS and CdSe, but it cannot suppress anodic corrosion of the CdTe electrode. 10 More recently, research interest in CdS-and CdSe-based liquid junction solar cells has been rejuvenated because of the emergence of quantum dots.…”

Electrocatalytic sulfur electrodes for CdS/CdSe quantum dot-sensitized solar cells

“…À0.45 V vs. normal hydrogen electrode) can be used to stabilize QD-sensitized photoelectrodes against photocorrosion, thereby stabilizing the photocurrents and extending the durability of the QDSSCs. [9][10][11] When employing a polysulfide electrolyte, however, commonly used Pt and Au counter electrodes are only poorly active, mainly because their surface activity and conductivity are suppressed as a result of adsorption of the sulfur atoms. [10][11][12] Therefore, instead of using Pt and Au electrodes, metal sulfides such as cobalt sulfide (CoS), nickel sulfide (NiS), and copper sulfide (CuS) have become promising candidates as electrocatalysts for polysulfide redox reactions in photoelectrochemical cells (PECs).…”

“…To support our reasoning, we further measured the redox potentials (E redox ) of these polysulfide electrolytes. 9,17 From the potentiostatic currentpotential (I-V) data (Fig. S6), we determined the values of E redox at 0.5, 1.0, and 2.0 M Na 2 S to be À0.533, À0.682, and À0.714 V, respectively.…”

Interfacial Electron Transfer Reactions in CdS Quantum Dot Sensitized TiO2 Nanocrystalline Electrodes

“…When the I 3 À /I À electrolyte [61] (redox potential, E red : þ 0.45 V versus NHE [45]), typically employed for Ru dye-sensitized solar cells, was used, the IPCE spectrum indicated no response in the visible wavelength range (>400 nm). A similar result was noted with the Fe 3þ /Fe 2þ electrolyte [63]), consisting of 2 M Na 2 S and 3 M S in water. The data clearly suggest the photocurrent response/amplitude is not dependent on the electrolyte redox potential, since the QD valence-band edge potential is located more positively than the bulk band edge ( þ1.6 V versus NHE).…”