Successes and Issues in the Growth of Moad and MoSe2 on Ag(111) by the E-ALD Method

Abstract

This paper explores the conditions for the electrodeposition of Moad (molybdenum adlayer) on Ag(111) from alkaline aqueous solution. Moreover, the first stages of the growth of MoSe2 are also presented, performing the deposition of Sead on the deposited Moad. The deposition of Moad on Sead/Ag(111) was also explored. MoSe2 is of interest due to its peculiar optoelectronic properties, making it suitable for solar energy conversion and nanoelectronics. In this study, electrodeposition techniques were exploited for the synthesis process as more sustainable alternatives to vacuum based techniques. The electrochemical atomic layer deposition (E-ALD) method emerges as a suitable technique to grow inorganic semiconductor thin films thanks to its fulfillment of the green energy predicament and a strict structural and morphological control, and this approach has gathered the attention of the scientific community. Indeed, E-ALD exploits surface limited reactions (SLRs) to alternate the deposition of chemically different atomic layers constituting a compound semiconductor. Thus, E-ALD is one of the most promising electrodeposition techniques for the growth of thin-film of compound semiconductors under a strict structural and morphological control. On this ground, E-ALD can be considered an ideal technique for the growth of 2D materials.

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

“…[6][7][8] In this context, wet electrochemistry methods seem to be promising candidates to comply with these needs; since electrodeposition from aqueous solutions succeeded in growing high-quality layers of semiconducting crystalline materials in multiple instances. [9][10][11][12][13] On the other hand, the fabrication of p-n junctions using wet chemical approaches is challenging because of the difficulties encountered in determining the right electrochemical deposition conditions for the subsequent layers deposition without altering or dissolving the film already deposited [14][15][16][17] .…”

“…Being a high‐cost/environmentally risky technology involving high energy consumption, [5] several research groups are trying to develop new methods to build up semiconductor junctions requiring the minimum amount of valuable material, less energy, and lower environmental impact [6–8] . In this context, wet electrochemistry methods seem to be promising candidates to comply with these needs; since electrodeposition from aqueous solutions succeeded in growing high‐quality layers of semiconducting crystalline materials in multiple instances [9–13] . On the other hand, the fabrication of p–n junctions using wet chemical approaches is challenging because of the difficulties encountered in determining the right electrochemical deposition conditions for the subsequent layers deposition without altering or dissolving the film already deposited [14–17] .…”

Optimization and Characterization of Electrodeposited Cadmium Selenide on Monocrystalline Silicon

“…The semiconductor nature of Si makes finding the right deposition conditions a difficult task since the exchange of electrons between the electrode and the solution is severely limited compared to metal electrodes and is influenced by the lighting conditions. While the deposition of CdSe on metals is now a well-known practice in the scientific field [36][37][38][39], as well as other semiconductors (CdS [40], MoSe 2 [41], Bi 2 Se 3 [42]), its deposition on Si has been scarcely explored.…”