August 15, 2019

Chemical deposition of antimony sulfide & silver antimony sulfide

The following photographs show the first 30 minutes of the solution reaction for chemical deposition of antimony sulfide thin films. This material is a p-type semiconductor. It is deposited as an amorphous source (Sb-S). The films have the necessary content to produce an orthorhombic lattice after heating above 250 ºC.


Antimony sulfide is used for the research of thin-film solar cells with the following configuration TCO/CdS/Absorber/BackContact.  This film is achieved using the formula reported in the paper I publish during my Ph.D. program (With no AgNO3).  Find it here.

For tips about deposition, feel free to write a comment!

[1] J. Capistrán Martínez, P.K. Nair, Photoconductive thin films of AgSbS2 with cubic crystalline structure in solar cells, Physica Status Solidi (a). 212 (2015) 2869–2876. doi:10.1002/pssa.201532496.

Initial deposition condition temperature near 10 ºC

The reaction of the Sb-S solution begins after 10 minutes. 

The color of the reaction change completely at 30 minutes, this color will be maintained until the controlled precipitation finish. 

After 3-4 hours of deposition, the films look good, there is adherence to the glass substrate and specular reflection in the surface. 

July 11, 2019

Water molecule using Burai 1.3 and Quantum Espresso

Course: Electronic properties of semiconductors by AB-INITIO  

Profesor: Dr. Raciel Jaimes López  (Postdoctoral at IER-UNAM) 

Simulation of water molecule formation using Burai 1.3 and Quantum Espresso
Viewer by Jmol
Last month I attended the course Electronic properties of semiconductor by AB-Initio at IER-UNAM, on the 1st day we had a quick view about the background of DFT (Density Functional Theory), plane waves and pseudopotentials. During the course, we learn about the open-code Quantum Espresso software which is used for electronic-structure calculation and materials modeling at nano-scale.
Here I share the  methodology I follow for the example water-molecule    

  1. Install  BURAI1.3 on MAC (includes Quantum-Espresso)
  2. Install MPI for MAC
  1. Open BURAI  and choose examples/XYZ: Water molecule (