Zero-dimensional hybrid iodobismuthate derivatives: from structure study to photovoltaic application

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photovoltaics

Background:

• Lead-free perovskite materials are crucial for developing environmentally friendly solar cells.
• Existing lead-free options often face challenges in stability or efficiency.
• Iodobismuthates are a class of compounds being explored as alternatives.

Purpose of the Study:

• To synthesize and characterize a novel zero-dimensional lead-free iodobismuthate material.
• To investigate its structural properties and compare it with related compounds.
• To evaluate its potential as a light-absorbing material in photovoltaic devices.

Main Methods:

• Synthesis of (MA)3[BiI6]·3MACl via orthogonal solvent permeation.
• Single-crystal X-ray diffraction for structural analysis.
• Density Functional Theory (DFT) calculations for electronic structure.
• Fabrication and testing of photovoltaic devices.

Main Results:

• Successfully synthesized a zero-dimensional iodobismuthate, (MA)3[BiI6]·3MACl, with isolated hexaiodobismuthate(iii) anions.
• Compared its structure and dimensionality with dinuclear Bi2I93- compounds.
• Discovered an undocumented second-order phase transition in MA3Bi2I9 between 160 K and 190 K.
• Achieved a 1.09% power conversion efficiency in a photovoltaic device using the new material.

Conclusions:

• The synthesized zero-dimensional iodobismuthate shows potential as a lead-free light absorber for solar cells.
• Structural and computational analysis provides insights into structure-property relationships.
• Further research into optimizing film morphology and device architecture is warranted.