Abel Presley Gomes presented on semiconductor devices. The presentation introduced semiconductors and their properties, the two types of semiconductors - intrinsic and extrinsic. It described key semiconductor components like diodes, transistors and how they work. Transistors were invented in 1948 and consist of two back-to-back p-n junctions with an emitter, base and collector. The presentation highlighted advantages of semiconductors like their use in microcircuits, strength, longevity and switching abilities.