The space charge region (RLZ) is the region that builds up in the pn junction between two differently doped semiconductors
: one positively doped and one negatively doped. This region is called the junction in semiconductors. The junction is characterized by the electrons in the n-doped semiconductor and the holes in the p-doped semiconductor, whose concentration is different. Therefore, an electric field
builds up in the space charge region and an electric potential is created which causes the electrons and holes to drift into the other charge region.