Synthesis and characterization of CsSnI3 thin films

Applied Physics Letters

Volumn 96, Issue 22, 2010, Pages

  Shum, Kai ^a   Chen, Zhuo ^a   Qureshi, Jawad ^a   Yu, Chonglong ^a   Wang, Jian J ^b   Pfenninger, William ^b   Vockic, Nemanja ^b   Midgley, John ^b   Kenney, John T ^b  

^a CITY UNIVERSITY OF NEW YORK   (United States)

^b OmniPV Inc   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

BAND GAPS; BAND-GAP SEMICONDUCTORS; FIRST-PRINCIPLES; POLYCRYSTALLINE; ROOM TEMPERATURE; SEMICONDUCTOR THIN FILMS; SYNTHESIS AND CHARACTERIZATION;

OXIDE MINERALS; PEROVSKITE;

THIN FILMS;

EID: 77953598296     PISSN: 00036951     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.3442511     Document Type: Article

References (10)

1. D. Scaife, P. Weller, and W. Fisher, J. Solid State Chem. JSSCBI 0022-4596 9, 308 (1974). 10.1016/0022-4596(74)90088-7
2. P. Mauersberger and F. Huber, Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. ACBCAR 0567-7408 B36, 683 (1980). 10.1107/ S0567740880004128
3. K. Yamada, S. Funabiki, H. Horimoto, T. Matsui, T. Okuda, and S. Ichiba, Chem. Lett. CMLTAG 0366-7022 20, 801 (1991). 10.1246/cl.1991.801
4. I. Borriello, G. Gantel, and D. Ninno, Phys. Rev. B PRBMDO 0163-1829 77, 235214 (2008). 10.1103/PhysRevB.77.235214
5. CASTEP simulation tool was used for this work; www.accelrys.com. The computational results on the total potential energy and electronic states of a given crystal structure were based on the density functional module CASTEP. Prior to the energy band structure calculation of a crystal structure, the type of crystal structure was determined by an energy minimization procedure in which the potential energy was calculated by varying a lattice scaling factor, by fine-tuning the Sn-I-Sn (or Sn-Cl-Sn) titling angles in ab -plane and in c -direction, as well as by changing Cs positions.
6. b, and ck =π /c
7. We have experimented different stoichiometric ratios of CsI to SnI2 (or SnCl2). The resulting films always give a characteristic PL emission peak around 950 nm although its intensity varies slightly. We have also characterized various samples using x-ray fluorescence (XRF) and energy dispersive x-ray analysis (EDS). For an example, with the 1-to-1 ratio of CsI/ SnI2, an atom ratio was found by XRF to be 1:0.9:2.3 for Cs:Sn:I after annealing, indicating slight loss of tin and iodine atoms during annealing. The EDS spectra were also acquired at various locations of annealed samples with no separated regions of CsI and SnI2 (or SnCl2 in case of CsI/ SnCl2 layered samples). For the fixed 1-to-1 stoichiometric ratio, the chemical formula for the CsI/ SnI2 reaction is CsI+ SnI2 → CsSnI3; while for the CsI/ SnCl2 reaction, three possible reactions that lead to CsSnI3-x Clx (x=0, 1, 2, and 3) structures are as follows: (1) CsI+ SnCl2 → CsSnICl2, (2) 2CsI+2 SnCl2 → CsSnI2 Cl+ CsSnCl3, and (3) 3CsI+3 SnCl2 → CsSnI3 +2 CsSnCl3.
8. CRYSTALMAKER simulation package (www.crystalmaker.com) was used to generate the electron diffraction patterns and XRD traces using the CsSnI3 unit cell obtained through our energy-minimization procedure.
9. The matching planes in sequence of diffraction efficiency from 47% to 3% are as follows: (2- 24), (2- 2- 4), (2, 2- 4), (22 4-), (0 4- 0), (0 4 0), (0 2- 0), (0 2 0), (1- 3- 2), (1 3- 2-), (1- 32), (13 2-), (1- 1- 2), (1 1- 2-), (1- 12), (11 2-), (2- 04), (204), (2- 44), and (2- 44).
10. Optical Processes in Semiconductors, edited by, J. I. Pankove, (Dover, New York, 1971).