We have developed a mathematical model able to predict the dependence of the current density, j0, in the dc limit, on the thickness of a photoactive semiconductor layer, d, in contact with an electrolyte. The model considers the application of an external bias. The theoretical analysis has been done by means of a diffusive model, where the excess of charges moves by diffusion in the presence of a generation term, due to the incident light, and a recombination term, proportional to the excess of charge carriers. We show that a non-monotonic dependence of j0 vs. d is expected. For small d, the photocurrent density is proportional to d and the proportionality constant is related to both the attenuation of the light in the photoactive semiconductor layer and to the applied potential. In the opposite limit of large d, the current tends to a constant value that is dependent on both the light intensity and the applied bias. Our theoretical predictions are in qualitative agreement with the experimental data reported in literature for BiVO4 films. © 2017 Elsevier B.V.

Non-monotonic dependence of the current density on the thickness of the photoactive layer / Saracco, Guido; Barbero, Giovanni; HERNANDEZ RIBULLEN, SIMELYS PRIS; Ionescu, ANCA LUIZA. - In: JOURNAL OF ELECTROANALYTICAL CHEMISTRY. - ISSN 1572-6657. - ELETTRONICO. - 788:(2017), pp. 61-65. [10.1016/j.jelechem.2017.01.069]

Non-monotonic dependence of the current density on the thickness of the photoactive layer

SARACCO, GUIDO;BARBERO, GIOVANNI;HERNANDEZ RIBULLEN, SIMELYS PRIS;IONESCU, ANCA LUIZA
2017

Abstract

We have developed a mathematical model able to predict the dependence of the current density, j0, in the dc limit, on the thickness of a photoactive semiconductor layer, d, in contact with an electrolyte. The model considers the application of an external bias. The theoretical analysis has been done by means of a diffusive model, where the excess of charges moves by diffusion in the presence of a generation term, due to the incident light, and a recombination term, proportional to the excess of charge carriers. We show that a non-monotonic dependence of j0 vs. d is expected. For small d, the photocurrent density is proportional to d and the proportionality constant is related to both the attenuation of the light in the photoactive semiconductor layer and to the applied potential. In the opposite limit of large d, the current tends to a constant value that is dependent on both the light intensity and the applied bias. Our theoretical predictions are in qualitative agreement with the experimental data reported in literature for BiVO4 films. © 2017 Elsevier B.V.
File in questo prodotto:
File Dimensione Formato  
Post print after profs (JEAC_Saracco'17).pdf

Open Access dal 04/02/2019

Descrizione: Post-print after peer-review & proofs
Tipologia: 2. Post-print / Author's Accepted Manuscript
Licenza: Creative commons
Dimensione 516.28 kB
Formato Adobe PDF
516.28 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2667270
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo