Use of conventional sources of energy to generate electricity is
increasing rapidly due to growing energy demands. This is a
major cause of pollution as well and also is an environmental
concern for future. Considering this, there is lot of R&D going on in the field of alternate energy sources with recent advancements in technology. One of the most recent advancement is the perovskite solar technology in the photovoltaics industry. The power conversion efficiency of perovskite solar cells has been improved from 9.7 to 20.1% within 4 years which is the fastest advancement ever in the photovoltaic industry. Such a high photovoltaic performance can be attributed to optically high absorption characteristics of the hybrid lead perovskite materials. In this review, different perovskite materials are breifly discussed along with the fundamental details of the hybrid lead halide perovskite materials. The fabrication techniques, stability, device structure and the chemistry of the perovskite structure are also briefly described aiming for a better understanding of these materials and thus highly efficient perovskite solar cell devices. The main focus of this resarch is to understand possible methods to reduce toxicity due to lead and to improve Perovskite stability.
2. Overview
1. Introduction
2. Origin and History
3. Solar Perovskites
4. Methylammonium Lead Halide Perovskite
5. Chemistry of CH3NH3PbX3 solar perovskites
6. Fabrication and Laboratory preperation
7. Factors to be addressed
8. Our Statement
3. Origin And History
Perovskite was first discovered in the Ural mountains of Russia by Gustav
Rose in 1839.
It was named after the Russian mineralogist Lev Perovski.
Found in the Earth’s mantle
4. Introduction
Perovskite is any mineral which has ABX3crystal structure, A and B are 2 cations
of very different sizes and X is an anion that bonds to both.
Most Common type is crystal structure for CaTiO3 which is also known as
Perovskite structure.
Synthetic Perovskites have been identified as possible inexpensive base materials
for high - efficiency of up to 20%.
High future potential: PCE – boomed from 3.8% to 20%
5.
6. What Are Solar Perovskites ?
• All perovskites are not solar
•Perovskite structured compound
• ‘Perovskite solar cell' is derived from the ABX3 crystal structure of the absorber
materials
• Most common perovskite absorber is methylammonium lead trihalide
CH3NH3PbX3 (optical bandgap between 1.5 and 2.3 eV)
8. Methylammonium Lead Halide
Perovskites (MALX)
Hybrid Organic Inorganic Semiconductor
Inorganic - Lead (Strong light absorption, Provide high efficiencies, even
above 20 % as per NREL)
Organic- Methyl Ammonium (Soluble in Polar Solvents, provide low
temperature processing - low cost and energy saving)
9. •Tuning the bandgap by adjusting the amount of halogen.
•Introduce with Silicon cell for higher efficiencies.
12. Cross-sectional scanning electron microscope (SEM) image of 270-nm-thick mixed halide
CH3NH3PbI3xClx absorber layer with hole-quenching layer of spiro-OMeTAD
14. Degradation Factor
•The instability of the Methyl Ammonium Lead Halide remains a major
obstacle to commercialization.
•In the presence of moisture, the perovskite undergoes rapid decomposition
(15 hours to 2 days) which results in significant decline in device
`performance.
•Test Results reveal that unencapsulated perovskite solar cells reported in
80% drop in PCE over a 24h period.
•Even more concerning is the decomposition to PbI2 because it is sparingly
soluble in water and this would result in extreme toxicity.
16. Contd.
Normalized steady state photoluminescence (PL) with
photoexcitation at 500 nm, and absorption taken with reflectance and
transmission employing an integrating sphere of the tin-based and
lead-based perovskites CH3NH3SnI3 and CH3NH3PbI3 respectively.
18. References
1. Band alignment of the hybrid halide perovskites CH3NH3PbCl3, CH3NH3PbBr3 and CH3NH3PbI3
2. Keith T. Butler, Jarvist M. Frost and Aron Walsh
3. Recent progress in efficient hybrid lead halide perovskite solar cells – Jin Cui, Hualiang Yuan, Hong Lin et;al.
4. Crystallography and Chemistry of Perovskites Mats Johnsson and Peter Lemmens (Dept. Inorg. Chemistry, Stockholm University)
5. Perovskite Solar cells: An emerging photovoltaic technology Nam-Gyu Park (SKKU)
6. Perovskite Solar Cells: Film Formation and properties- Tze Bin Song, Qi Chen, Huanping Zhou, et al.
7. www.solarpowerworldonline.com/2015/04/the-perfect-marriage-silicon-and-perovskite-solar-cells/
8. Lead-free organic–inorganic tin halide perovskites for photovoltaic applications -Nakita K. Noel, Samuel D. Stranks, Antonio Abate,
Christian Wehrenfennig, Simone Guarnera, Amir-Abbas Haghighirad, Aditya Sadhanala, Giles E. Eperon, Sandeep K. Pathak,
Michael B. Johnston, Annamaria Petrozza, Laura M. Herza and Henry J. Snaith
9. A Layered Hybrid Perovskite Solar-Cell Absorber with Enhanced Moisture Stability-Ian C. Smith, Eric T. Hoke, Diego Solis-Ibarra,
Michael D. McGehee, and Hemamala I. Karunadasa
