On the Electrochemical Growth of a Crystalline p–n Junction From Aqueous Solutions

Our society largely relies on inorganic semiconductor devices which are, so far, fabricated using expensive and complex processes requiring ultra-high vacuum equipment. Here we report on the possibility of growing a p-n junction taking advantage of electrochemical processes based on the use of aqueous solutions. The growth of the junction has been carried out using the Electrochemical Atomic Layer Deposition (E-ALD) technique, which allowed to sequentially deposit two different semiconductors, CdS and Cu2S, on an Ag(111) substrate, in a single procedure. The growth process was monitored in situ by Surface X-Ray Diffraction (SXRD) and resulted in the fabrication of a thin double-layer structure with a high degree of crystallographic order and a well-defined interface. The high-performance electrical characteristics of the device were analysed ex-situ and show the characteristic feature of a diode.