Solid-State Colloidal CuInS2 Quantum Dot Solar Bulk Heterojunctions

Colloidal copper indium sulfide (CIS) nanocrystals (NCs) are Pb- and Cd-free alternatives for use as absorbers in quantum dot solar cells. In a heterojunction with TiO2, non-annealed ligand-exchanged CIS NCs form solar cells yielding a meager power conversion efficiency (PCE) of 0.15%, with photocur...

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Detalles Bibliográficos
Autores: So, David, Pradhan, Santanu, Konstantatos, Gerasimos
Tipo de recurso: artículo
Fecha de publicación:2016
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/100673
Acceso en línea:https://hdl.handle.net/2117/100673
Access Level:acceso abierto
Palabra clave:Solar cells
quantum dot
Cèl·lules solars
Àrees temàtiques de la UPC::Física
Descripción
Sumario:Colloidal copper indium sulfide (CIS) nanocrystals (NCs) are Pb- and Cd-free alternatives for use as absorbers in quantum dot solar cells. In a heterojunction with TiO2, non-annealed ligand-exchanged CIS NCs form solar cells yielding a meager power conversion efficiency (PCE) of 0.15%, with photocurrents plummeting far below predicted values from absorption. Decreasing the amount of zinc during post-treatment leads to improved mobility but marginally improves device performance (PCE = 0.30%). By incorporating CIS into a porous TiO2 network, we saw an overall drastic improvement in device performance, reaching PCEs of 1.16%, mainly from an increase in short circuit current density (Jsc) and fill factor (FF) and a 10-fold increase in internal quantum efficiency (IQE). We have determined that by moving from a bilayer to a bulk heterojunction architecture, we have reduced the trap-assisted recombination as seen in changes in the ideality factor, the intensity dependence of the photocurrent and transient photocurrent (TPC) and photovoltage (TPV) characteristics.