Radiation thermodynamics limits to solar cell efficiency

27 02 2014

On the thermodynamics of light trapping in solar cells

Uwe Rau, Thomas Kirchartz, Nature Materials 13, 103–104 (2014)

In this paper, Rau and Kirchartz establish “the equation that leads to physically correct and meaningful results in all situations and should be considered for future optimizations of light management in solar cells.”


q, elementary charge; Eg, band gap energy; k, Boltzmann’s constant; T , temperature of the cell ; bb:blackbody.

It is not no easy to see the meaning of the terms just at first sight if you are not familiar with it, but the important point is that it works correctly when you come to apply it…



HOPV Conference 2014 in Lausanne

26 02 2014

The Hybrid and Organic Photovoltaics Conference 6th edition will be celebrated in Lausanne

  • Evening reception: Sunday, 11th May 2014
  • Scientific program: 11-14 May, 2014

This year there are abundant contributions on the emergent perovskite solar cells, including important highlights by the key scientists in this field.

There are also major keynotes on dye;sensitized solar cells, organic solar cells, quantum dot solar cells, and advanced aspects of photovoltaic mechanisms in general.

The conference will take place at the brand new Swiss Tech Convention Center. It is located on the campus of the  École Polytechnique Fédérale de Lausanne (EPFL). Its futuristic design features a glass façade equipped with dye sensitized solar cells.

Michael Grätzel
École Polytechnique Fédérale de Lausanne, Switzerland

Mohammad Khaja Nazeeruddin
École Polytechnique Fédérale de Lausanne, Switzerland

Jean-Luc Brédas
Georgia Tech, USA

Anders Hagfeldt
Uppsala Universitet, SE

Karl Leo
Technische Universitaet Dresden, DE

Nam-Gyu Park
Sungkyunkwan University, KR

Edward Sargent
University of Toronto, CA

Eli Yablonovitch
Berkeley University, USA

Yun Chi
National Tsing Hua University, TW

Peter Erk

Andreas Hinsch
Fraunhofer Institute for Solar Energy Systems, DE

René Janssen
Eindhoven University of Technology, NL

Alex Jen
University of Washington, USA

Michael McGehee
Stanford School of Engineering, USA

Gerald J. Meyer
Johns Hopkins University, USA

David Mitzi
IBM T.J Watson Research Center, USA

Tsutomu Miyasaka
Toin University of Yokohama, JP

Ursula Rothlisberger

Hiroshi Segawa
The University of Tokyo, JP

Sang-Il Seok
Korea Research Institute of Chemical Technology, KR

Henry Snaith
University of Oxford, UK

Natalie Stingelin
Imperial College London, UK

Yanfa Yan
The University of Toledo, ES

Yang Yang
UCLA Engineering, USA

Chen-Yu Yeh
National Chung Hsing University, TW

The Gala Dinner will take place in a boat sailing from Lausanne towards Montreux/Geneva. It will be a very special event…



Perovskite solar cell: see it crystallize

25 02 2014

Whatch the video by Joe Manser, with appearances by Prashant Kamat, Mercouri Kanatzidis, and colleagues.

and see the related article Tapping Solar Power With Perovskites


Here is what you get in this process


This is a SEM picture of CH3NH3PbI3 crystal, made by Nam-Gyu Park, professor at Sungkyunkwan University  (in the picture, in our way for dinner in Seoul).

You see the perovskite record-fighting people at the next HOPV Conference in Lausanne.

Nam-Gyu Park and JB

Perovskite solar cells record at 16.2%

24 02 2014

The new record of 16.2% for a perovskite solar cell has been publsihed at the NREL table. This has been achieved by Sang Il Seok, at South Korean institute KRICT, located in Daejeon.

Earlier in 2013 Seok showed an important result about modulation of the bandgap of the perovskite, by replacing Br for I in the X site of the perovskite structure (MA B X3), Nano Letters, 2013, 13, 1764–1769.

Now new solvent-engineering technology established by Seok enabled the formation of extremely uniform and dense perovskite layers, and remarkably improved the performance with high reproducibility.

With this result the perovskite solar cell continues to rise at extremely fast speed, and issues of stability and reproducibility begin to be seriously addressed by many researchers.

JB and Sang Il Seok

efficiency_chart 14 02 23