New Light-Harvesting Materials Using Accurate and Efficient Bandgap Calculations

Electronic bandgap calculations are presented for 2400 experimentally known materials and the bandgaps are compared for 20 randomly chosen compounds forming an unconventional set of ternary and quaternary materials. It is shown that the computationally cheap GLLB-SC potential gives results in good agreement with the more advanced and demanding eigenvalue-self-consistent GW. Using this methodology, 25 light harvesting candidate materials are obtained and 5 of them appear to have a realistic possibility of being used as photocatalyst in a one-photon water splitting device.

Ivano E. Castelli, Falco Hüser, Mohnish Pandey , Hong Li , Kristian S. Thygesen , Brian Seger, Anubhav Jain, Kristin A. Persson, Gerbrand Ceder, and Karsten W. Jacobsen

Advanced Energy Materials 2015, 5, 1400915

High-throughput materials design is becoming more and more important in materials science thanks to theory developments that make computer simulations more reliable, and to an increase in computational resources. During the last decade, the search for stable binary and ternary alloys, batteries, carbon capture and storage, photovoltaics, dye sensitized solar cells, and water splitting materials has been guided by computational studies.

The huge amount of data produced during these studies has been collected in several databases, for example, the Materials Project database, the AFLOWLIB consortium and the Computational Materials Repository. Experimental data are also collected into databases such as the Inorganic Crystal Structure Database (ICSD) and the Landolt-Börnstein database: the former contains around 160 000 crystal structures, the latter collects the electronic, magnetic, thermodynamic properties of 250 000 compounds. The ICSD database is one of the most complete repositories for crystal information. Despite this, the electronic properties are not always available and so they are not included.

Advanced Energy Materials figure 1 

Histogram of the GLLB-SC bandgaps for all the 2400 calculated materials (in
blue).  We consider the two energy thresholds 1 eV/atom (in red) and 0 eV/atom
(in green) for the stability in water, which is calculated at zero potential
( U = 0 V vs NHE) and neutral pH.

One of the tasks for computational condensed matter scientists is to fill in the missing information in experimental databases. In this paper, we present the calculations of around 2400 bandgaps of known materials using the GLLB-SC potential by Gritsenko, van Leeuwen, van Lenthe, and Baerends, (GLLB) adapted by Kuisma et al. to include the correlation for solids (-SC). The GLLB-SC potential is implemented in the framework of density functional theory (DFT) in the electronic structure code GPAW. The structures under investigation are obtained from the Materials Project database. As of March 2014, it contains around 50 000 structures optimized with DFT from the ICSD entries. We then compare the bandgaps of 20 compounds calculated with different methods, namely local density approximation (LDA), GLLB-SC, GW approximations (G0W0 , GW0 , and GW) and the range-separated hybrid functional by Heyd, Scuseria, and Ernzerhof (HSE06). At the end, we apply a screening procedure, discussed in detail and used in previous works, to find new light harvesting materials suitable for water splitting devices.

 

 

 

 

Contact

Karsten Wedel Jacobsen
Professor
DTU Physics
+45 45 25 31 86