Homojunction Cu₂O Solar Cells Fabricated with Various Impurity-Doped Epitaxially Grown n-Type Cu₂O Thin Film by Electrochemical Deposition

Al:Cu2O n-Type Semiconductors─Electrochemical Fabrication of Heterojunction and Homojunction Photovoltaic Devices

“…Cu 2 O is intrinsically a p-type semiconductor with a band gap energy of 2.1 eV, while n-type Cu 2 O semiconductor layers can be prepared by either introducing impurity elements such as Mn and Cl into Cu 2 O layers or electrodeposition in an acidic copper­(II)-acetate aqueous solution. , Two types of Cu 2 O solar cells, the heterojunction type primarily featuring an n-ZnO layer , and the homojunction type, were fabricated using various processes. The best performances of 9.5 and 4.74% were achieved for the heterojunction and homojunction, respectively, through the introduction of wide band gap oxide semiconductor layers such as Ga 2 O 3 , , (Ga 0.975 Al 0.025 ) 2 -O 3 , and Zn 0.38 Ge 0.62 O as buffer layers between the p-Cu 2 O and n-type semiconductor layers. The potential exists for further enhancing the photovoltaic performance of homojunction solar cells due to the minimal lattice mismatch between the p- and n-Cu 2 O semiconductor layers, in contrast to the heterojunction cells with an n-ZnO layer, which have a large lattice mismatch.…”