Copper–indium–selenide quantum dot-sensitized solar cells

Abstract

We present a new synthetic process of near infrared (NIR)-absorbing copper-indium-selenide (CISe) quantum dots (QDs) and their applications to efficient and completely heavy-metal-free QD-sensitized solar cells (QDSCs). Lewis acid-base reaction of metal iodides and selenocarbamate enabled us to produce chalcopyrite-structured CISe QDs with controlled sizes and compositions. Furthermore, gram-scale production of CISe QDs was achieved with a high reaction yield of ~73%, which is important for the commercialization of low-cost photovoltaic (PV) devices. By changing the size and composition, electronic band alignment of CISe QDs could be finely tuned to optimize the energetics of the effective light absorption and injection of electrons into the TiO2 conduction band (CB). These energy-band-engineered QDs were applied to QDSCs, and the quantum-confinement effect on the PV performances was clearly demonstrated. Our best cell yielded a conversion efficiency of 4.30% under AM1.5G one sun illumination, which is comparable to the performance of the best solar cells based on toxic lead chalcogenide or cadmium chalcogenide QDs.

Flexible quantum dot light-emitting diodes for next-generation displays

“…2b, c). [26][27][28][29][30][31][32][33][34] High color purity is also an important characteristic for display applications. CdSe QDs show very sharp emission spectra (FWHM of~30 nm) and wide color gamuts compared to the conventional standard emission spectra of the commercialized high-definition television (Fig.…”

Designed Assembly and Integration of Colloidal Nanocrystals for Device Applications

“…As shown in Figure b, doctor blading produces relatively thick NC films (up to several micrometers) . For example, the process has been employed to obtain several‐micrometer‐thick TiO 2 NC layers in dye‐ or QD‐sensitized solar cells, or electrodes made by conducting NCs (Figure c) . As an advanced/modified method of doctor blading, Mayer rods, periodical grooved rods, or wire‐wound rods, have been employed in the blading procedure to make a uniform film thickness without a spacer.…”

“…e) An SEM cross‐sectional image of the blend of CdSe tri‐/tetra‐pods and P3HT for the bulk‐heterojunction solar cell. b) Reproduced with permission . Copyright 2013, Royal Chemical Society.…”

“…TiO 2 NCs are commonly employed as an electrode to increase the interfacial area for effective charge transport . Anatase TiO 2 NCs are spread on the transparent electrode by doctor‐blading or screen‐printing techniques, and then sintered to form a nanoporous TiO 2 electrode (Figure b) . Semiconductor NCs, which act as photosensitizers, are drop‐cast and then smeared into the pores of the TiO 2 electrodes.…”

Reactively sputtered nickel nitride as electrocatalytic counter electrode for dye- and quantum dot-sensitized solar cells

“…Since 1991, after the pioneering report by Brian O’Regan and Michael Grätzel, mesoscopic dye-sensitized solar cells (DSCs) have attracted great attention due to their favorable characteristics: high performance and reliability, applicability of varied materials and designs, low manufacturing cost, and environmental compatibility1234. In addition, quantum dot-sensitized solar cells (QDSCs), in which semiconducting quantum dots (QDs) are utilized as the light-harvesting units, also have been intensively studied due to QDs’ attractive properties, such as the ability for band energy tuning, high absorption coefficients, and the multiple exciton generation effect5678.…”