Iodomethane-Mediated Organometal Halide Perovskite with Record Photoluminescence Lifetime
2016 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 35, 23181-23189 p.Article in journal (Refereed) Published
Organometallic lead halide perovskites are excellent light harvesters for high-efficiency photovoltaic devices. However, as the key component in these devices, a perovskite thin film with good morphology and minimal trap states is still difficult to obtain. Herein we show that by incorporating a low boiling point alkyl halide such as iodomethane (CH3I) into the precursor solution, a perovskite (CH3NH3PbI3-xClx) film with improved grain size and orientation can be easily achieved. More importantly, these films exhibit a significantly reduced amount of trap states. Record photoluminescence lifetimes of more than 4 mu s are achieved; these lifetimes are significantly longer than that of pristine CH3NH3PbI3-xClx films. Planar heterojunction solar cells incorporating these CH3I-mediated perovskites have demonstrated a dramatically increased power conversion efficiency compared to the ones using pristine CH3NH3PbI3-xClx. Photoluminescence, transient absorption, and microwave detected photoconductivity measurements all provide consistent evidence that CH3I addition increases the number of excitons generated and their diffusion length, both of which assist efficient carrier transport in the photovoltaic device. The simple incorporation of alkyl halide to enhance perovskite surface passivation introduces an important direction for future progress on high efficiency perovskite optoelectronic devices.
Place, publisher, year, edition, pages
AMER CHEMICAL SOC , 2016. Vol. 8, no 35, 23181-23189 p.
iodomethane; perovskite solar cell; photoluminescence lifetime; surface passivation; trap state; transient absorption; microwave detected photoconductivity
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-131886DOI: 10.1021/acsami.6b05770ISI: 000382902800051PubMedID: 27529636OAI: oai:DiVA.org:liu-131886DiVA: diva2:1034911
Funding Agencies|National Basic Research Program of China (973 Program) [2012CB932402]; National Natural Science Foundation of China (NSFC) [U1432106]; Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD); Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University2016-10-132016-10-112016-10-13