Solution‐Processed High‐Quality Cu₂O Thin Films as Hole Transport Layers for Pushing the Conversion Efficiency Limit of Cu₂O/Si Heterojunction Solar Cells

Abstract

Cuprous oxide (Cu2O) is a nontoxic and earth‐abundant semiconductor material, which is a promising candidate for low‐cost photovoltaic applications. Although Cu2O‐based solar cells have been studied for a few decades, they still suffer from disappointing photovoltaic performance due to its high trap‐state density and inferior carrier collection efficiency. Herein, a facile solution method is demonstrated to synthesize high‐quality Cu2O films with low defects as hole transport layers (HTLs) and the Cu2O/Si heterojunction solar cells are fabricated. Moreover, a variety of interfacial engineering and light management strategies are adopted to push the efficiency limit of Cu2O/Si solar cells, including a Ag transparent conductive layer, HNO3 passivation, Mg electrode back contact, and MoOx antireflection layer, which enable the boosting of carrier separation and reduce the loss of incident solar light, yielding a record high power conversion efficiency of 9.54%. This work may pave the way for economical and environment‐friendly use of Cu2O/Si heterojunction solar cells in daily life.

Multiple Heterojunction System of Boron Nitride‐Graphene/Black Phosphorene as Highly Efficient Solar Cell

“…Thus, the PCE of BN-GR/BP heterojunction can be calculated as around 21.3%, which is far higher than that of nanocarbonbased photovoltaics [39] (9-13%) and single-bulk-heterojunction solar cell [38] (10%), and is also at a higher level among the heterojunctions that have been reported so far. [40][41][42][43] Clearly, BN-GR/BP heterojunction has great potential in the field of photoelectric conversion devices in the future. Furthermore, the influence of different ratios of GR and BN on the electronic structure of cross-linked BN-GR, the BN 1 -GR 3 /BP (BN:GR = 1:3) and BN 3 -GR 1 /BP (BN:GR = 3:1) heterojunctions are also studied in this work (Figures S4 and S5, Supporting Information).…”

“…Thus, the PCE of BN‐GR/BP heterojunction can be calculated as around 21.3%, which is far higher than that of nanocarbon‐based photovoltaics [ 39 ] (9–13%) and single‐bulk‐heterojunction solar cell [ 38 ] (10%), and is also at a higher level among the heterojunctions that have been reported so far. [ 40–43 ] Clearly, BN‐GR/BP heterojunction has great potential in the field of photoelectric conversion devices in the future.…”

Enhanced Photoelectrochemical Water Splitting by Surface Modified Electrodeposited n‐Cu2O Thin Films

“…Cuprous oxide (Cu 2 O) is an inexpensive, abundant, and nontoxic semiconductor material suitable for large‐scale solar energy applications. It owes intriguing optical [ 1 ] and electrical properties [ 2 ] which tends the investigators to draw their attention to develop its applications in photovoltaic [ 3,4 ] and photoelectrochemical (PEC) devices. [ 5,6 ] A low cost and efficient solar energy to chemical energy conversion possibility via hydrogen generation is one of the most important and prominent research areas today.…”

An investigation of photovoltaic devices based onp‐typeCu2Oandn‐typeγ‐WO3junction through an electrolyte solution containing a redox pair

“…Generally, the film heterojunction occurs from semiconductor film deposition by techniques such as sputtering or plasma deposition, immediately overlapping both types of films. In this way, the p‐ type and n‐ type films are put into contact without an electrolyte solution 31‐35 . The operation of the device with p–n heterojunction occurs due to the difference in charge concentration at the interface of two semiconductors 36,37 .…”

“…In this way, the p-type and n-type films are put into contact without an electrolyte solution. [31][32][33][34][35] The operation of the device with p-n heterojunction occurs due to the difference in charge concentration at the interface of two semiconductors. 36,37 Unfortunately, this type of solar cell still requires expensive technology for film preparation, 29,38,39 as is the case of silicon solar cells, which are p-n heterojunction semiconductors that demand expensive equipment and a large structure for their manufacture, including cleanrooms.…”