Hot Plate Experiment: Semiconductor Behavior Analysis

This lecture discusses the hot plate experiment involving silicon semiconductors. The instructor explains the behavior of n-type and p-type silicon when subjected to temperature gradients. The experiment begins with a silicon plate, heated from one side, leading to the excitation of free electrons. This results in a depletion zone on the heated side and an accumulation zone on the cooler side, creating an electric field. The instructor illustrates the charge distribution, showing negative charges on the left and positive charges on the right. The lecture further explores the currents involved, including drift and diffusion currents, and introduces the concept of thermal current due to temperature gradients. The instructor emphasizes the balance of these currents at equilibrium. The experiment is quantitatively analyzed, demonstrating the measurable voltage differences generated in n-type and p-type silicon under similar conditions. The lecture concludes with practical implications of these findings in semiconductor applications.