Charge transfer characterization of ALD-Grown TiO₂ protective layers in silicon photocathodes

A critical parameter for the implementation of standard high-efficiency photovoltaic absorber materials for photoelectrochemical (PEC) water splitting is its proper protection from chemical corrosion while remaining transparent and highly conductive. Atomic layer deposited (ALD) TiO₂ layers fulfill...

Descripción completa

Detalles Bibliográficos
Autores: Ros, Carles|||0000-0002-9148-2767, Andreu, Teresa|||0000-0002-2804-4545, Hernández-Alonso, María Dolores, Penelas-Pérez, Germán, Arbiol i Cobos, Jordi|||0000-0002-0695-1726, Morante, Joan Ramon|||0000-0002-4981-4633
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:194887
Acceso en línea:https://ddd.uab.cat/record/194887
https://dx.doi.org/urn:doi:10.1021/acsami.7b02996
Access Level:acceso abierto
Palabra clave:Atomic layer deposition
PEC cells
Protecting overlayers
Silicon
Solar hydrogen production
Titanium dioxide
Water splitting
Descripción
Sumario:A critical parameter for the implementation of standard high-efficiency photovoltaic absorber materials for photoelectrochemical (PEC) water splitting is its proper protection from chemical corrosion while remaining transparent and highly conductive. Atomic layer deposited (ALD) TiO₂ layers fulfill material requirements while conformally protecting the underlying photoabsorber. Nanoscale conductivity of ALD TiO₂ protective layers on silicon based photocathodes has been analyzed, proving that the conduction path is through the columnar crystalline structure of TiO₂. Deposition temperature has been explored from 100 to 300 ºC, and a temperature threshold is found to be mandatory for an efficient charge transfer, as a consequence of layer crystallization between 100 and 200 ºC. Completely crystallized TiO₂ is demonstrated to be mandatory for long term stability, as seen in the 300 h continuous operation test.