Introduction 4417 2. Precursor Requirements 4418 3. Precursors for II-VI Materials 4418 3.1. Precursors for II-VI Thin Films 4418 3.1.1. Alternate Chalcogenide Precursors 4419 3.1.2. Adducts of Metal Alkyls 4419 3.1.3. Single-Molecule Precursors 4419 3.2. Precursors for II-VI Nanoparticles 4425 4. Precursors for III-V Materials 4428 4.1. Precursors for III-V Thin Films 4428 4.1.1. Alternative Group V Sources 4428 4.1.2. III-V Adducts 4429 4.1.3. III Nitrides 4429 4.1.4. III Phosphides and Arsenides 4430 4.1.5. III Antimonides 4431 4.2. Precursors for III-V Nanoparticles 4431 5. Precursors for III-VI Materials 4432 5.1. Precursors for III-VI Thin Films 4432 5.1.1. Thiolato Complexes 4432 5.1.2. Thiocarbamato Complexes 4433 5.1.3. Xanthato and Monothiocarbamato Complexes 4433 5.1.4. Dichalcogenoimidodiphosphinato Complexes 4433 5.2. Precursors for III-VI Nanoparticles 4434 6. Precursors for IV-VI Materials 4434 6.1. Precursors for IV-VI Thin Films 4434 6.2. Precursors for IV-VI Nanoparticles 4437 7. Precursors for V-VI Materials 4437 7.1. Precursors for V-VI Thin Films 4437 7.2. Precursors for V-VI Nanoparticles 4440 8. Conclusions 4441 9. Acknowledgments 4442 10. References 4442

Power generation through photovoltaics (PV) has been growing at an average rate of 40% per year over the last decade; but has largely been fuelled by conventional Si-based technologies. Such cells involve expensive processing and many alternatives use either toxic, less-abundant and or expensive elements. Kesterite Cu(2)ZnSnS(4) (CZTS) has been identified as a solar energy material composed of both less toxic and more available elements. Power conversion efficiencies of 8.4% (vacuum processing) and 10.1% (non-vacuum processing) from cells constructed using CZTS have been achieved to date. In this article, we review various deposition methods for CZTS thin films and the synthesis of CZTS nanoparticles. Studies of direct relevance to solar cell applications are emphasised and characteristic properties are collated.

Nickel phosphide and nickel selenide semiconductors are potential materials for photoelectrochemical solar cells. 1,2 They also have interesting electrical and magnetic properties and have promising applications as catalysts 3 and in sensors. 4 Nickel phosphide is an n-type semiconductor with a band gap of 1.0 eV, whereas the selenide is a p-type with a band gap of 2.0 eV. There are only few reports on the deposition of nickel phosphide films which include by magnetron sputtering, 5 electrodeposition, 6 electroless deposition, 7 or the reaction of orthophosphoric acid on a nickel substrate. 1 Nickel selenide films were prepared by electrodeposition, 2 solution growth, 8 reactive diffusion, 9 or chemical vapor deposition (CVD) methods. 10 As far as we know there is no report on the deposition of a Ni 0.85 Se/Ni 2 P heterostructure. Single source precursor (SSP) chemistry has attracted considerable interest for the growth of semiconductor thin films and nanoparticles. 11 Herein we report the synthesis and characterization of imido-bis-(diisopropylthioselenophosphinate) nickel(II), Ni[ i Pr 2 P(S)NP(Se) i -Pr 2 ] 2 , an interesting complex used as SSP for the growth of nickel phosphide (Ni 2 P) or nickel selenide (Ni 0.85 Se) and in sequence for Ni 0.85 Se/Ni 2 P layers. There are reports for the formation of different phases of the same material from a SSP 12 but to best of our knowledge there are no reports for the deposition of phosphide and selenide materials from the same precursor.The SSP was synthesized by the deprotonation of the ligand [ i -Pr 2 P(S)NHP(Se) i Pr 2 ] 13 using sodium methoxide to form the anion which is subsequently reacted with nickel(II) nitrate hexahydrate in methanol to produce a dark-red precipitate. Recrystallization of the complex from toluene gave red crystals. X-ray crystallographic studies reveal that a nickel atom is tetrahedrally coordinated through the sulfur and selenium atoms (Figure 1). The crystal structure shows the presence of independent monomeric units which are separated by normal van der Waals distances. The sulfur and selenium atoms are disordered as observed for the Pt[ i Pr 2 P(S)-NHP(Se) i Pr 2 ] 13 complex and are refined with equal occupancies for both atoms. The six-membered NiSSeP 2 N ring adopts puckered pseudo-boat conformation.Decomposition was studied by thermogravimetric analysis (TGA) (N 2 atmosphere at 10 °C min -1 ) which reveals a single-step decomposition between 300 and 368 °C. Low-pressure metalorganic (LP-MOCVD) experiments were carried out using a custom-built cold-walled low-pressure reactor tube which has been described elsewhere. 14 Deposition was carried out on a glass substrate for 60 min at temperatures between 475 and 375 °C, and the precursor temperature was kept constant at 300 °C. Nickel phosphide films were deposited at temperatures of 475, 450, and 425 °C, whereas nickel selenide films were deposited at temperatures of 400 or 375 °C. X-ray diffraction pattern (XRD) of the

A series of diorganotin complexes of dithiocarbamates [Sn(C4H9)2(S2CN(RR′)2)2] (R, R′ = ethyl (1); R = methyl, R′ = butyl (2); R, R′ = butyl (3); R = methyl, R′ = hexyl (4); and [Sn(C6H5)2(S2CN(RR′)2)2] (R, R′ = ethyl (5); R = methyl, R′ = butyl (6); R, R′ = butyl (7); R = methyl, R′ = hexyl (8) were synthesized. Single-crystal X-ray structures of 2, 3, and 8 were determined. Thermogravimetric analysis (TGA) showed single-step decomposition for the complexes 1, 3, and 5–8, and double-step decomposition for the complexes 2 and 4 between 195 °C and 325 °C. Complexes 1–4 were used as single-source precursors for the deposition of SnS thin films by aerosol-assisted chemical vapor deposition (AACVD) at temperatures from 400 °C to 530 °C. Orthorhombic SnS thin films were deposited from all four complexes at all deposition temperatures. The films were characterized by UV–vis spectroscopy, powder X-ray diffraction (p-XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and also electrical resistivity measurements.

No abstract

Lead sulfide has been grown from single molecular precursors within a polymer matrix to form networks of PbS nanocrystals. These materials are model systems for the processing of polymer-nanoparticle layers for flexible hybrid photovoltaic devices. Processing is achieved by spin coating a solution containing the precursor and polymer on to a substrate, followed by heating of the film to decompose the precursor. The effect of precursor chemistry has been explored using: lead(II) dithiocarbamates, their 1,10-phen adducts, and lead(II) xanthates with different alkyl chain lengths (butyl, hexyl, and octyl). The xanthates were found to be more promising precursors giving control over nanocrystal size and shape on variation of the alkyl chain length. The lead(II) octyl xanthate complex causes anisotropic growth, forming PbS nanowires within the polymer matrix.

A new approach to the one-step synthesis of cadmium selenide (CdSe) quantum dots is reported using the air stable complex cadmium imino-bis(diisopropylphosphine selenide); the ligand is readily prepared from elemental selenium and the precursor, quantum dots of comparable quality to those prepared by conventional methods are obtained.

No abstract