Abstract: Composite materials useful for devices such as photoelectrochemical solar cells include a substrate, a metal oxide film on the substrate, nanocrystalline quantum dots (NQDs) of lead sulfide, lead selenide, and lead telluride, and linkers that attach the NQDs to the metal oxide film. Suitable linkers preserve the 1s absorption peak of the NQDs. A suitable linker has a general structure A-B-C where A is a chemical group adapted for binding to a MOx and C is a chemical group adapted for binding to a NQD and B is a divalent, rigid, or semi-rigid organic spacer moiety. Other linkers that preserve the 1s absorption peak may also be used.

Abstract: Embodiments of linkers for binding semiconductor quantum dots (QDs) to metal oxides are disclosed. The linkers have a general formula F1-A-(F2)z wherein F1 is —COOH, —COO?, —PO3H2, —PO3H?, —B(OH)2, —BO2H?, —SO3H, —SO3?, —NH2, —SH, or —S?; A is aryl, heteroaryl, aliphatic, or heteroaliphatic; and z?1 and each F2 independently is —PO3H2, —PO3H?, —B(OH)2, —BO2H?, —SO3H, —SO3?, or z?2 and each F2 independently is —COOH, —COO?, —PO3H2, —PO3H?, —B(OH)2, —BO2H?, —SO3H, or —SO3?, or z?2 and (F2)z collectively is an oxysilane moiety comprising z lower alkoxy groups bound to silicon. Methods of binding QDs to metal oxides with the disclosed linkers also are disclosed, as well as devices including the QD-functionalized metal oxides.

Abstract: Composite materials useful for devices such as photoelectrochemical solar cells include a substrate, a metal oxide film on the substrate, nanocrystalline quantum dots (NQDs) of lead sulfide, lead selenide, and lead telluride, and linkers that attach the NQDs to the metal oxide film. Suitable linkers preserve the 1s absorption peak of the NQDs. A suitable linker has a general structure A-B-C where A is a chemical group adapted for binding to a MOx and C is a chemical group adapted for binding to a NQD and B is a divalent, rigid, or semi-rigid organic spacer moiety. Other linkers that preserve the 1s absorption peak may also be used.

Abstract: Photoelectrochemical solar cells (PECs) consisting of a photoanode were prepared by direct deposition of independently synthesized CdSe nanocrystal quantum dots (NQDs) onto a nanocrystalline TiO2 film (NQD/TiO2), aqueous Na2S or Li2S electrolyte and a Pt counter electrode. The light harvesting efficiency (LHE) of the NQD/TiO2 photoanode is significantly enhanced when the NQD surface passivation is changed from tri-n-octylphosphine oxide (TOPO) to a smaller ligand (e.g. n-butylamine (BA)). Using NQDs with a shorter passivating ligand, BA, leads to a significant enhancement in both the electron injection efficiency at the NQD/TiO2 interface and charge collection efficiency at the NQD/electrolyte interface, with the latter attributed mostly to a more efficient diffusion of the electrolyte through the pores of the photoanode.