TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The step of providing the etching composition involves spraying the etching composition on the CdTe-containing layer; or moving the CdTe-containing layer through a tank containing the etching composition. The etching composition is provided for a time period of approximately 1 second to approximately 60 seconds. The etching composition is not rinsed by deionized water from the CdTe-containing layer. The etching composition is provided at room temperature. In method (M2), the step of providing the etching composition involves spraying the first mixture on the CdTe-containing layer followed by spraying the second mixture on the CdTe-containing layer; or moving the CdTe-containing layer through a first tank containing the first mixture and a second tank containing the second mixture. The method (M2) further involves rinsing the CdTe-containing layer after moving the CdTe-containing layer through the first tank containing the first mixture and prior to moving the CdTe-containing layer through the second tank containing the second mixture. The first mixture is provided for a time period of approximately 1 second to approximately 60 seconds. In method (M2), the etching composition is provided at room temperature. Preferred Composition: The etching composition has a pH of approximately 1 to approximately 5. Preferred Components: The oxidizer is hydrogen peroxide.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The acid is selected from gluconic acid, acetic acid, and/or citric acid. The complexing agent is selected from benzotriazole, cysteine, a glycolic acid ethoxylate lauryl ether surfactant, and/or a polyethylene glycol surfactant. EXAMPLE - Cadmium-tellurium (CdTe) films were etched by the following etching composition comprising: 25 wt./wt.% acetic acid, 0.75 wt./wt.% hydrogen peroxide, 1 wt./wt.% polyethylene glycol surfactant and water (quantity sufficient). The initial Cd/Te ratio was 1:1. The CdTe ratio became 0.05-0.1:1 after approximately 10 seconds to approximately 20 seconds contact with the etching composition followed by a light rinse with deionized water. The final ratio depended upon etch time.