Over the past decade, semiconductors have been of great interest and are currently found in numerous devices such as: computers, cell phones, and medical equipment. Semiconductors are the integral component of solar cells, converting solar energy into electricity.

This research studies the photoactivity and stability of semiconductors cadmium selenide (CdSe) and poly(o-methoxyaniline) (POMA) deposited on highly oriented pyrrolic graphite (HOPG). The CdSe-POMA deposits were electrochemically deposited on HOPG using cyclic voltammetry. The composites were deposited in the following order: (1) CdSe before POMA (CdSe/POMA), (2) POMA before CdSe (POMA/CdSe), and (3) CdSe and POMA simultaneously (CdSe+POMA). For the sequential depositions, the deposition of CdSe and POMA were performed sequentially so that the surface consisted of the desired hybrid. The CdSe layer was deposited for 20 cycles from a solution of 5 mM CdSO₄ and 1 mM SeO₂ in 0.1 M HClO₄. The polymerization of POMA was accomplished by electrochemical cycling for 5 cycles from a 0.06 M o-anisidine solution in 0.1 M HClO₄. The deposition of CdSe+POMA was performed by electrochemical cycling for 20 cycles in a solution of 5 mM CdSO₄, 1 mM SeO₂, and 0.06 M o-anisidine in 0.1 M HClO₄.

The photoactivity and stability of the deposits were studied using open circuit potentiometry (OCP), cyclic voltammetry (CV), and chronoamperometry (i/t) in 0.1 M Na₂SO₃. The CdSe/POMA deposit had the greatest photopotential at around 200 mV while POMA/CdSe and CdSe+POMA presented lower photopotentials at 30 mV and 14 mV respectively. Chronoamperometric studies found that CdSe/POMA had the greatest photocurrent density of 17 µA/cm² compared to 0.05 µA/cm² for POMA/CdSe and 0.42 µA/cm² for CdSe+POMA. Photoelectrochemical measurements suggest that POMA/CdSe and CdSe+POMA deposits were less stable than CdSe/POMA. X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) were used to analyze the surface. The surface morphology and chemical composition of the deposits were studied before and after photo-studies to observe the degree of degradation after the sample was exposed to light. Measurements found that the POMA/CdSe and CdSe+POMA deposits degraded more than CdSe/POMA, suggesting that depositing the polymer over the CdSe film might be necessary in reducing the degree of degradation when the sample is exposed to light.