The photoelectric semiconductor, poly- N-vinylcarbazole (PVK) provides a specific embedding resin for studies of semi-thin sections (50 nm) in the photoemission electron microscope (PEEM). The essential advantages of PVK consist of immediate emission and a long usable observation period, so that it has become possible to study spatial associations of structures in large area semithin sections and serial sections. Using PVK, emission current densities may be reached which permit the imaging of structures without heavy metal staining. Image formation by low-energy electrons from a blocking layer (contact between semiconductor and metal) as light-sensitive site is discussed.