Tuning Semiconductor Performance of Nickel Complexes through Crystal Transformation

Area of Science:

• Materials Science
• Solid-State Chemistry
• Organic Electronics

Background:

• Square-planar nickel complexes exhibit diverse properties.
• Polymorphism in metal complexes can significantly influence material characteristics.
• Tuning semiconductor properties is crucial for electronic device applications.

Purpose of the Study:

• Investigate crystal transformation between green (1-G) and red (1-R) polymorphs of NiL₂.
• Analyze the impact of crystal transformation on the semiconductor properties of NiL₂.
• Understand the mechanism behind conductivity tuning in NiL₂-based devices.

Main Methods:

• Experimental studies including heating and solvent soaking for crystal transformation.
• Crystallographic and Powder X-ray Diffraction (PXRD) for structural analysis.
• Electrical conductivity measurements of NiL₂ devices.
• Theoretical calculations for electronic property analysis.

Main Results:

• NiL₂ exhibits reversible crystal transformation between 1-G and 1-R polymorphs triggered by temperature and solvent.
• Electrical conductivity of NiL₂ devices increases significantly upon transformation from 1-G to 1-R.
• Both polymorphs were identified as p-type semiconductors with distinct hole mobilities.
• Theoretical calculations elucidated the structure-property relationships.

Conclusions:

• The crystal structure of NiL₂ polymorphs dictates their semiconductor properties.
• Conductivity tuning is achievable through controlled crystal transformation via heating or solvent treatment.
• NiL₂-based materials show potential for tunable semiconductor applications.