The past five years have witnessed an unprecedented advance in the field of solar cells1 with perovskite metal halide, CH3NH3PbI3, as the primary semiconductor of interest. The archetypical semiconductor forms nearly defect free, crystalline films at low temperatures that exhibit high optical absorption, long-range charge transport, and efficient charge collection, yielding solar cells that rival the performance of industry standard silicon, with verified record efficiency of 21%. Perovskite solar cells will progress towards higher efficiencies with new materials and device concepts, however, a mere incremental approach of process and materials improvements will not surpass efficiencies of single crystal silicon solar cells. A key way forward is through the realization that these perovskite materials are excellent laser gain materials2 with outstanding luminescent properties. Premised on the principle that a high performance solar cell must be an excellent light-emitting device,3 next generation of optoelectronics devices would be driven by a combination of rational end-use designed materials, defect-free systems,4 and mechanisms to maximise external photoluminescence efficiencies. This presentation will address broad palette of elemental substitutions, solid solutions, and multidimensional families that will provide the next step towards the advances of the perovskite solar cells and light-emitting devices. Challenges and opportunities in perovskite materials beyond methyl ammonium lead iodide5 with particular emphasis on their optoelectronic properties would also be addressed. References  Boix PP, Agarwala S, Koh TM, Mathews N, Mhaisalkar SG, Perovskite Solar Cells: Beyond Methylammonium Lead Iodide, J Physical Chemistry Letters, 2015, 6, 5, 898-907  G Xing, N Mathews, S. S. Lim, N. Yantara, X. Liu, D. Sabba, M Grätzel, S Mhaisalkar and TC Sum; Low-Temperature Solution-Processed Wide Wavelength Tunable Perovskites for Lasing; Nature materials, 2014, 13, 476-480  O. D. Miller, E. Yablonovitch and S. R. Kurtz, IEEE Journal of Photovoltaics, 2012, 2, 303-311  G Xing, N Mathews, S Sun, S S Lim, YM Lam, M Gratzel, S Mhaisalkar, TC Sum; Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH3NH3PbI3; Science, 2013, 342, 344-347  HK Mulmudi, D Sabba, WL Leong, PP Boix, R Ramanujam, T Baikie, C Shi, H Ding, R Ramesh, M Asta, M Graetzel, SG Mhaisalkar, N Mathews; Lead-Free Halide Perovskite Solar Cells with High Photocurrents Realized Through Vacancy Modulation; Advanced Materials, 2014, 26, 41, 7122-7128  N Yantara, S Bhaumik, F Yan, D Sabba, HA Dewi, N Mathews, PP Boix, HV Demir, and SG Mhaisalkar, Inorganic Halide Perovskites for Efficient Light-Emitting Diodes, J. Phys. Chem. Lett. 2015, 6, 4360?4364  T Krishnamoorthy, H Ding, C Yan, WL Leong, T Baikie, Z Zhang, M Sherburne, S Li, M Asta, N Mathews, SG Mhaisalkar; Lead-free Germanium Iodide Perovskite Materials for Photovoltaic Application; J. Mater. Chem. A, 2015,3, 23829-23832
Subodh Mhaisalkar is the Tan Chin Tuan Centennial Professor in the School of Materials Science & Engineering at the Nanyang Technological University (NTU), Singapore. Subodh is also the Executive Director of the Energy Research Institute @ NTU (ERI@N), a pan-University multidisciplinary research institute for innovative energy solutions. Prior to joining NTU in 2001, Subodh has over 10 years of research and engineering experience in the microelectronics industry and his areas of expertise and research interests includes semiconductor technology, perovskite solar cells, printed electronics, and energy storage. Subodh received his Bachelors’ degree from IIT-Bombay and his MS/Ph.D. degrees from The Ohio State University. Prof Subodh’s main areas of research comprise perovskite solar cells, printable electronics, and materials for energy storage. Common to all these projects are methods of solution processing of semiconductors, fundamental device physics studies, and device integration. For his work in Organic Thin Film Transistors, Subodh and his team won the IEEE 2008 George E. Smith Award for their work in printable electronics. Subodh is also the recipient of Ohio State University’s Professional Achievement Award 2012, the Nanyang Award for Innovation and Entrepreneurship in 2012, and Singapore National Day Award 2014 - The Public Administration Medal (Silver). Major research projects include Competitive Research Program Funding from the National Research Foundation on “Nanonets: New Materials & Devices for Integrated Energy Harnessing & Storage;” Polymer & Molecular Electronics with A*STAR, and a DARPA funded program on printed charge storage devices. As the Executive-Director of the Energy Research Initiative @ NTU (ERI@N), Subodh leads a pan-university effort, coordinating all research activities within the University pertaining to energy and promoting interactions and collaborations between colleges in the area of energy research. In raising $220 M in research funding, ERI@N with a staff-strength of 191 full-time staff and 130 PhD scholarships has set up 33 Industry partnership projects, including joint-laboratories (on NTU Campus) with global industry leaders BMW, Johnson Matthey, Vestas, Gamesa, Rolls-Royce, and Bosch. Prof Subodh has graduated 15 Masters and PHD students and is currently supervising a group of 13 PhD students and research fellows. Subodh has published more than 325 research papers and has active collaborations with UCLA, Northwestern University, CEA/CNRS France, IIT-Bombay, NUS, and local research institutes. Subodh received his Bachelors’ degree from IIT-Bombay and his MS/Ph.D. degrees from The Ohio State University.