How to read a scientific paper in just three steps

Reading on paper is an old school way to annotate
and highlight the most interesting elements

For a scientist, reading is a must responsibility in the modern world of information, this task allows us to update the state of the art of the current research. For example, the objective of my work is to reproduce and improve antimony sulfo-selenide thin-film solar cells. Therefore, the first thing I did before experimental research It was to read the updated literature. As I am in touch with the author of the paper of interest I asked him about it's last published paper where their group develops Sb-S-Se photovoltaic mini-module prototypes. 

P.K. Nair*, J.D.G. Sánchez, L.G. Martínez, P.Y.G. Ayala, A.K.M. Peñaloza, A.B. León, Y.C. García, J. Campos Álvarez, M.T.S. Nair, Chemically Deposited Antimony Sulfide Selenide Thin Film Photovoltaic Prototype Modules, ECS J. Solid State Sci. Technol. 8 (2019) Q89–Q95. doi:10.1149/2.0101906jss.

To fully understand, I almost read a scientific paper three times:

• First: Print it or read it on PDF (Mendeley could help), the important thing here is to read from the beginning to the end as soon as possible.
• Second: Make annotations for later discussion and highlights from the most important elements you can find on the text.
• Third: Write a resume, this will allow you to save the essential information in the same notebook of literature review. I prefer to write it on the Blogspot or a note on the Evernote app following the next template.

Read more, to discover the structure or template for paper review, here you are going to write just the notes and highlighted parts. This is my way to learn fast. If you have an alternate strategy please feel free to share it in the comments section.

Paper: Chemically deposited antimony sulfide selenide thin film photovoltaic prototype modules

Authors: P. K. Nair,  José Diego Gonzaga Sánchez, Laura Guerrero Martínez, Perla Yoloxóchitl García Ayala, Ana Karen Martínez Peñaloza, Alessandra Beauregard León, Yareli Colín García, José Campos Álvarez, and M. T. S. Nair

Link: ECS Journal of Solid State Science and Technology, 8 (6) Q89-Q95 (2019)

Abstract

We present thin film antimony sulfide selenide prototype photovoltaic modules of area, seven cm2 and conversion efficiency (η) of 3.5%. The thin films of Sb2SxSe3-x (x, 0.8–1.6) of 120–180 nm in thickness were deposited on FTO/CdS(80 nm) substrates at 80°C from chemical bath containing potassium antimony tartrate, thioacetamide and sodium selenosulfate. Thin film of CdS of 80 nm in thickness was deposited from a chemical bath at 80°C during 65 min on fluorine-doped SnO2 (FTO). The solar cell structure FTO/CdS/Sb2SxSe3-x/C had colloidal graphite paint of area, 0.7 cm× 0.7 cm. This cell structure was heated at 300°C during 30 min in a nitrogen ambient to create a carbon-doped antimony chalcogenide layer. Silver paint was applied to the carbon electrode and on FTO around it. Prototype modules had seven series connected cells of one cm2 each with a total area of seven cm2. Solar cell with varying composition of Sb2SxSe3-x along its thickness had a η of 3.88% at an open circuit voltage (Voc) of 0.44 V and short circuit current density of 18.3 mA/cm2. Prototype modules lighted-up blue light emitting diodes at a power, 5–15 mW.

Highlights

• The best solar cell is:   Voc = 441 mV, Jsc = 18.34 mA/cm2, FF = 0.48 and efficiency = 3.88 % measured under standar conditions of 1 sun (Solar simulator). 
• Application of carbon paint over chalcogenide layer and subsequent heating of the entire cell structure would create a carbon-doped antimony chalcogenide layer

Device fabrication 

• Substrate:  TEC7 
• Window layer:  CdS by chemical deposition (80 nm)
• Absorber layer: Sb-S-Se by sequential chemical deposition  (180 nm)
• Back contact: Graphite paint (SPI) / Silver paint (N2 heat treatment, 300 ºC) 

Characterization techniques 

• EDS - Over finished solar cells 
• GIXRD - Over solar cell 
• T and R - Optical  for calculation of absorption coefficient, bandgap  and photogenerated current (JL) 
• JC curve for solar cell and mini-modules
• EQE for solar cells 

Notes: 

• This work is open for improvements in all the constitutive components of the solar cell device. 

Fabrication of Titanium dioxide as a compact layer for Perovskite and thin-film solar cells

Special thanks for Dra Hailin Zao Hu at IER-UNAM who let me collaborate and learn from their group the methodology for TiO2 compact layer deposition.  All the training was possible with the assistance of Ph.D. student Fabian and undergraduate  Ing. Gabriela Abrego from UTEZ.

Preparing TCO with magic tape  for HRT layer deposition 

Spin coater  and micropipette are the essential tools for TiO2 deposition 

First heating of the compact layer over a hot plate : low temperature

Second and final heating - Sintering TiO2 on a muffle furnace : high temperature

Compact TiO2 layer deposited over a TCO for thin-film chalcogenide or Perovskite solar cells.