Summary
Fourier transmission spectroscopy and laser calorimetry reveal impurity bands in chemical vapor deposition (CVD) zinc selenide (ZnSe). Surface impurities affect multiphonon absorption, deviating from expected behavior.
Area of Science:
- Materials Science
- Solid State Physics
- Spectroscopy
Background:
- Chemical vapor deposition (CVD) zinc selenide (ZnSe) is a crucial material in optical applications.
- Understanding bulk and surface impurities is vital for optimizing material properties.
- Impurity bands can significantly affect optical absorption characteristics.
Purpose of the Study:
- To characterize bulk and surface impurity bands in CVD ZnSe.
- To investigate the temperature dependence of absorption spectra.
- To differentiate the contributions of bulk and surface impurities to optical absorption.
Main Methods:
- Fourier transform infrared (FTIR) spectroscopy.
- Laser calorimetry.
- Temperature-dependent absorption measurements.
Main Results:
- Absorption between 1200-1800 cm⁻¹ is primarily attributed to bulk molecular impurities.
- Surface impurities contribute to absorption and cause deviations from expected multiphonon absorption behavior above 850 cm⁻¹.
- Temperature dependence studies reveal distinct characteristics of bulk versus surface impurity absorption.
Conclusions:
- Both bulk and surface impurities play a role in the optical properties of CVD ZnSe.
- Surface impurities introduce complexities in predicting multiphonon absorption.
- Accurate characterization requires considering both bulk and surface contributions.
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