Improved performance of InSe-based photoelectrochemical cells by means of a selective (photo)electrochemical etching

Abstract

It is shown that the performance of photoelectrochemical cells based on the lamellar material InSe can be considerably improved by means of a selective (photo)electrochemical etching. Whereas the cleavage Van de Waals plane (⊥ to c axis) shows little improvement, the photcurrent in the ∥ face (parallel to the c axis) is doubled (30 mA cm−2 under AM1 illumination). For n-type InSe a reverse bias (+1.5 V versus standard calomel electrode SCE) was employed during the photoetching, p-InSe electrodes were electrochemically etched by applying a forward bias (+1.5 V). In both cases, surface holes carry out the selective corrosion of the semiconductor surface which is another manifestation for the asymmetry played by holes and electrons on semiconductor surfaces. It is hoped that this finding will pave the way for the construction of high-efficiency solar cells based on a thin film made of lamellar materials.

Growth and Optical Properties of Ho Doped n-Type Indium Selenide

“…In conclusion, these results are in good agreement with the literature [2,7,9,17,20,27,28]. It is seen from the experimental absorption results that the band gap of n-InSe:Ho is greater than that of n-InSe.…”

“…The energy gap of 1.3 eV exists at 300 K with an indirect energy gap some 50 meV below the energy of the direct gap in InSe bulk crystals [18]. There are other reports about the indirect band gap of 1.2 eV [19], and the direct band gap of 1.32 eV in InSe single crystals [9,20]. Camassel et al [7] reported an investigation of the fundamental absorption edge of InSe under high-resolution conditions.…”

Porous Anodic Etching of p-Cd[sub 1−x]Zn[sub x]Te Studied by Photocurrent Spectroscopy

“…Anodic treatment not only leads to a chemical surface film, but also to important changes in electrode morphology. Several reports indicate that anodization of II-VI semiconductors causes surface pitting, [12][13][14][15][16][17][18][19][20][21] but the authors do not address the question of whether pores extend deeply below the surface; their work focuses on surface roughening and its important effects on the photoelectrochemical properties. Recently, we showed that anodic treatment can render p-Cd 0.95 Zn 0.05 Te porous across a thickness of more than 100 m, 22 and nanoporous layers with quantum size effects have been obtained by anodization of p-ZnTe.…”

Self-assembly of delocalized .pi.-stacks in solution. Assessment of structural effects

“…However, when 1.2 electrons/molecule was added, the X^s hifted to even longer wavelengths (beyond 2500 nm). This is preliminarily interpreted to mean that (11) Miller, L. L.; Zhong, C. J.; Kasai, P. H. Submitted for publication. (12) Heywang, G.; Bom, L; Fitzky, H.-G.; Hassel, T.; Hocker, J.;…”