Solid State Excitation‐Emission Spectroscopy for the Non‐Destructive Analysis of Band‐Gap & Defect States in Inorganic and Organic Semiconductors

Abstract

A new approach to analyze band‐gap and defect states within semiconductors is reported. Solid state excitation‐emission matrices are used to deconvolve spectral signatures that will be superimposed in 1D spectral space; for example, the 570 nm emission peak in ZnO whose emissive state is of a different physical nature depending on the excitation wavelength used. The broad applicability of the technique is shown for a library of widely studied inorganic semiconductors CdS, CdSe, ZnS, ZnSe, ZnO (analytical standard and nanorods), and TiO2. Anthracene is included as a representative example of an organic semiconductor. The developed approach can identify spectral features from the band gap, defects, and trace impurities and provide information on the relative contributions of the different emission pathways. The technique, based on using a plate‐reader conventionally used for the study of biological samples in solution has applicability in both academic and industrial settings for semiconductor studies and quality control applications.