page_title: P–n diode
section_title: Structure
hierarchical_section_title: P–n diode / Structure
caption_attribution_description: English: Two pn-diode structures: Mesa diode (top) and Planar diode (bottom)
context_page_description: A p–n diode is a type of semiconductor diode based upon the p–n junction. The diode conducts current in only one direction, and it is made by joining a p-type semiconducting layer to an n-type semiconducting layer. Semiconductor diodes have multiple uses including rectification of alternating current to direct current, detection of radio signals, emitting light and detecting light.
context_section_description: The figure shows two of the many possible structures used for p–n semiconductor diodes, both adapted to increase the voltage the devices can withstand in reverse bias. The top structure uses a mesa to avoid a sharp curvature of the p⁺-region next to the adjoining n-layer. The bottom structure uses a lightly doped p-guard-ring at the edge of the sharp corner of the p⁺-layer to spread the voltage out over a larger distance and reduce the electric field. (Superscripts like n⁺ or n⁻ refer to heavier or lighter impurity doping levels.)
caption: Mesa diode structure (top) and planar diode structure with guard-ring (bottom).
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