The document discusses electrodeposited cadmium sulfide (CdS) as the n-type semiconductor layer in copper indium gallium selenide (CIGS) thin film solar cells. Figure a-d show the visual appearance, surface morphology, transmittance, and crystal structure of the CdS films. Electrodeposition produces hexagonal CdS at room temperature with no post-treatment, and shows higher photoactivity than chemically bath deposited CdS. Photoelectrochemical measurements indicate that electrodeposited CdS on CIGS enhances light absorption and electron-hole separation compared to bare CIGS. The electrodeposition technique is advantageous as it reuses electrolytes and produces less toxic waste than chemical