Effect of Thickness on Structural and Optical Properties of Tetra‐tert‐ butyl‐2, 3‐naphthalocyanine Thin Films

I Dhanya,C S Menon

doi:10.1155/2011/752982

Abstract

Amorphous tetra‐tert‐butyl‐2, 3‐naphthalocyanine thin films have been deposited using physical vapor deposition technique under a varied thickness by adjusting the coating time. By analyzing the x‐ray diffraction, the structure of as deposited films is found to be non‐crystalline. Different optical properties of these thin films have been investigated by means of optical absorption and reflection spectra. Various optical constants like band gap energy, Eg the width of band tails of localized states into the gap, EU and steepness parameter, β gets calculated and the variation of different optical parameters like refractive index, extinction coefficient, dielectric constants, optical conductivity and surface and volume energy losses with photon energy are estimated.

Highlights

More complex options to porphyrines, naphthalocyanines have been extensively used as potential materials for optoelectronic and electronic devices for solar cells[1,2,3]
Tert-butyl substituted naphthalocyanine, as one of phthalocyanine derivatives is known for frequency and time domain spectral hole burning optical storage devices[4] due to the presence of large inhomogeneous broadening, relatively narrow holes at low temperatures and a built in proton photo transformation mechanism between different tautomers
Most studies related to phthalocyanine derivatives are addressed to the structural aspects of the molecular arrangement in thin films and in solution phase using UPS, XPS or NEXAFS5-8

Summary

Introduction

More complex options to porphyrines, naphthalocyanines have been extensively used as potential materials for optoelectronic and electronic devices for solar cells[1,2,3]. We are intended to prepare 2,11,20,29-tetra-tert-butyl2,3-naphthalocyanine (TTBNc) thin films and monitored the x-ray diffraction pattern, absorption and luminescence spectra. Thin film samples of TTBNc with varied thickness are investigated.

Results

Conclusion