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Pronounced Purcell enhancement of spontaneous emission in CdTe/ZnTe quantum dots embedded in micropillar cavities Appl. Phys. Lett. 101, 132105 (2012) Effects of Co content on the structural, luminescence, and ferromagnetic properties of Zn1−xCoxSy films J. Appl. Phys. 112, 063712 (2012) Mechanisms of infrared photoluminescence in HgTe/HgCdTe superlattice J. Appl. Phys. 112, 063512 (2012) Leaky mode analysis of luminescent thin films: The case of ZnO on sapphire J. Appl. Phys. 112, 063112 (2012) Observation of In-related collective spontaneous emission (superfluorescence) in Cd0.8Zn0.

A thin-film solar cell based on a Cu 2 ZnSnS 4 (CZTS) absorber layer deposited by pulsed laser deposition has been fabricated with an Al:ZnO (n-type) window layer and a CdS buffer layer. Some peaks attributed to ( 112), ( 200), ( 220), and (312) planes of CZTS appeared in an X-ray diffraction pattern of a thin film. The composition of the film was Sn-rich and the band gap energy was approximately 1.5 eV. A CZTS film annealed at 500 C in an atmosphere of N 2 had optical characteristics suitable for use in an absorber layer of a thin-film solar cell and was used for a solar cell. The CZTS thin-film solar cell with an active area of 0.092 cm 2 showed an open-circuit voltage of 546 mV, a short-circuit current of 6.78 mA/cm 2 , a fill factor of 0.48, and a conversion efficiency of 1.74%.

Photoreaction cycles of acidified bacteriorhodopsin (bRacid 605) at room temperature was studied by nanosecond and picosecond spectroscopy. A precursor of bathobacteriorhodopsin was found to be converted to bathobacteriorhodopsin within 30 ps. Spectra and formation times of batho‐ and lumibacteriorhodopsin are identical to those of bacteriorhodopsin in neutral suspension. However, lumibacteriorhodopsin lifetime is > 700 μs and the formation of metabacteriorhodopsin was not observed in low pH suspension. Thus, the decay process of lumibacteriorhodopsin plays an important role in the proton pump action.

PACS 71.55.Ht, 78.55.Hx Photoluminescence from Cu 2 ZnSnS 4 bulk single crystals was studied as a function of temperature and excitation power density. The bulk single crystals showed a broad luminescence between 1.1 and 1.45 eV. The peak energy of the photoluminescence was shifted to higher energy side when the excitation power density was increased. The origon of the photoluminescence was attributed to donor -acceptor pair recombination with an activation energy of 48 meV.

PACS 68. 84.60.Jt Cu 2 ZnSnS 4 (CZTS) thin films were prepared by post-annealing films of metal sulfides of Cu 2 S, ZnS and SnS 2 precursors deposited on soda-lime glass substrates by photo-chemical deposition (PCD) from aqueous solution containing CuSO 4 , ZnSO 4 , SnSO 4 and Na 2 S 2 O 3 . In this study, sulfurization was employed to prepare high quality CZTS thin films. Deposited films of metal sulfides were annealed in a furnace in an atmosphere of N 2 or N 2 +H 2 S(5%) at the temperature of 300˚, 400˚ or 500˚C. The sulfured films showed X-ray diffraction peaks from (112), (220), and (312) planes of CZTS and the peaks became sharp by an increase in the sulfurization temperature. CZTS thin film annealed in atmosphere of N 2 was S-poor. After annealing atmosphere was changed from N 2 into N 2 +H 2 S(5%), the decrease of a compositional ratio of sulfur could be suppressed.1 Introduction Cu 2 ZnSnS 4 (CZTS) has a structure obtained by replacing the indium (In) in chalcopyrite CuInS 2 with zinc (Zn) and tin (Sn), and has very suitable optical properties for an absorber layer of solar cell. Firstly, it has a band gap energy of 1.5 eV which is very close to the optimum value of absorber layer of solar cell. Secondly, it has an absorption coefficient over 10 4 cm -1 which is large enough to constitute thin film solar cell. From these significant features, CZTS is expected to be one of the promising materials for thin film solar cell. This material is non-toxic and the component elements are abundant in the crust of the earth and then inexpensive. Therefore, if we can use CZTS film as absorber of solar cells, we will be free from both of the resource saving problem and the environmental pollution. Photo-chemical deposition (PCD), which is employed in this report, is an interesting thin film growth method of a novelty because films can be grown in a short time and at low cost. There are reports in which ZnS, CdS, ZnSe, PbS and CZTS films were deposited by PCD [7][8][9][10][11][12][13].We reported in a previous paper that a CZTS film prepared by PCD and post-annealed at 400˚C was p-type semiconductor and showed photoconductivity and that X-ray diffraction peaks of CZTS were