Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes
Abstract
:1. Introduction
- The Cu2O absorption layer forms a sufficient number of electron-hole pairs (EHPs) but lacks the driving force to move minority carriers adequately because of its low carrier mobility. In other words, the efficiency of the charge separation and transport of photogenerated electrons was low; it is challenging to sufficiently utilize the photogenerated electrons for hydrogen generation reactions with only a single Cu2O layer.
2. Materials and Methods
2.1. Synthesis of Cu2O Photocathode
2.2. Preparation of Cu2O/AZO Heterojunction
2.3. Synthesis of TiO2 Passivation Layers and Pt Catalysts
2.4. Sample Characterization
2.5. PEC Measurements
3. Results and Discussion
3.1. Characterization of Cu2O/ZnO and Cu2O/AZO Structures
3.2. Electrical Characteristics of ZnO-Based Overlayers
3.3. Visible-Light PEC Behavior of Samples with Different Overlayers
3.4. Enhancement in Charge Transfer and PEC Activity
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Sample (Cycle) | Name |
---|---|
ZnO (20) × 5: 20 nm | ZnO |
(Al (1) + ZnO (20)) × 5 (ZnO end): 20 nm | AZ@AZO |
(Al (1) + ZnO (20)) × 5 + Al (1) (Al end): 20 nm | AA@AZO |
(ZnO (20) + Al (1)) × 5 (Al end): 20 nm | ZA@AZO |
(ZnO (20) + Al (1)) × 4 + (ZnO end): 20 nm | ZZ@AZO |
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Lee, H.H.; Kim, D.S.; Choi, J.H.; Kim, Y.B.; Jung, S.H.; Sarker, S.; Deshpande, N.G.; Suh, H.W.; Cho, H.K. Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes. Micromachines 2021, 12, 338. https://doi.org/10.3390/mi12030338
Lee HH, Kim DS, Choi JH, Kim YB, Jung SH, Sarker S, Deshpande NG, Suh HW, Cho HK. Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes. Micromachines. 2021; 12(3):338. https://doi.org/10.3390/mi12030338
Chicago/Turabian StyleLee, Hak Hyeon, Dong Su Kim, Ji Hoon Choi, Young Been Kim, Sung Hyeon Jung, Swagotom Sarker, Nishad G. Deshpande, Hee Won Suh, and Hyung Koun Cho. 2021. "Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes" Micromachines 12, no. 3: 338. https://doi.org/10.3390/mi12030338
APA StyleLee, H. H., Kim, D. S., Choi, J. H., Kim, Y. B., Jung, S. H., Sarker, S., Deshpande, N. G., Suh, H. W., & Cho, H. K. (2021). Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes. Micromachines, 12(3), 338. https://doi.org/10.3390/mi12030338