CuInS₂-Sensitized Quantum Dot Solar Cell. Electrophoretic Deposition, Excited-State Dynamics, and Photovoltaic Performance

Abstract

Ternary metal chalcogenides such as CuInS2 offer new opportunities to design quantum dot solar cells (QDSC). Chemically synthesized CuInS2 quantum dots (particle diameter, 2.6 nm) have been successfully deposited within the mesoscopic TiO2 film using electrophoretic deposition (150 V cm(-1) dc field). The primary photoinduced process of electron injection from excited CuInS2 into TiO2 occurs with a rate constant of 5.75 × 10(11) s(-1). The TiO2/CuInS2 films are photoactive and produce anodic photocurrent with a power conversion efficiency of 1.14%. Capping the TiO2/CuInS2 film with a CdS layer decreases the interfacial charge recombination and thus offers further improvement in the power conversion efficiency (3.91%). The synergy of using CdS as a passivation layer in the composite film is also evident from the increased external quantum efficiency of the electrode in the red region where only CuInS2 absorbs the incident light.

Colloidal synthesis of wurtzite CuInS2 nanocrystals and their photovoltaic application

“…Meanwhile, CuInS 2 quantum dots have been successfully synthesized and applied to sensitize mesoscopic TiO 2 film and 3.91% power conversion efficiency have been achieved [24]. In recent years, 1.14% power conversion efficiency of solar cells fabricated by aqueous CuInS 2 quantum dots have also been reported [25].…”

Facile modified cyclic electrophoretic deposition of hydrothermally prepared TiO2 nanocrystals and their application in dye sensitized solar cells

“…The larger P90 TiO 2 nanoparticles could also create considerable light scattering and improve the energy conversion efficiency [62,93,94]. Nevertheless, the hydrothermally grown TiO 2 nanocrystals with sizes around 20 nm have been increasingly applied in the photoanode of DSCs in recent years [25,77,95]. The reason could be attributed to the higher surface area and higher dye loading of these nanocrystals which could increase the efficiency [50,96].…”

UV light-assisted fabrication of Cu0.91In0.09S microspheres sensitized TiO2 nanotube arrays and their photoelectrochemical properties

“…However, considering environmental regulations, the intrinsic toxicity of Cd casts doubts on the future applicability of the Cd compounds, despite their excellent electrical and optical properties. In view of this, Cd-free alternative materials, such as I-III-VI 2 nanocrystals with fewer environmental impacts than Cd, were proposed in recent years [10,11]. Tetragonal CuInS 2 (CIS), which is a direct band gap semiconductor with E g = 1.55 eV, has many favorable features including high absorption coefficient (10 5 cm À1 ) and proper band gap well matched to the solar spectrum, as well as non-toxicity and good stability [12].…”