Open AccessOptoelectronic Properties in Near‐Infrared Colloidal Heterostructured Pyramidal “Giant” Core/Shell Quantum Dots
Author(s) -
Tong Xin,
Kong XiangTian,
Wang Chao,
Zhou Yufeng,
NavarroPardo Fabiola,
Barba David,
Ma Dongling,
Sun Shuhui,
Govorov Alexander O.,
Zhao Haiguang,
Wang Zhiming M.,
Rosei Federico
Publication year - 2018
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201800656
Subject(s) - materials science , quantum dot , photoluminescence , photocurrent , optoelectronics , wurtzite crystal structure , exciton , fabrication , nanoparticle , band gap , nanotechnology , zinc , physics , medicine , alternative medicine , pathology , quantum mechanics , metallurgy
Abstract Colloidal heterostructured quantum dots (QDs) are promising candidates for next‐generation optoelectronic devices. In particular, “giant” core/shell QDs (g‐QDs) can be engineered to exhibit outstanding optical properties and high chemical/photostability for the fabrication of high‐performance optoelectronic devices. Here, the synthesis of heterostructured CuInSe x S 2− x (CISeS)/CdSeS/CdS g‐QDs with pyramidal shape by using a facile two‐step method is reported. The CdSeS/CdS shell is demonstrated to have a pure zinc blend phase other than typical wurtzite phase. The as‐obtained heterostructured g‐QDs exhibit near‐infrared photoluminescence (PL) emission (≈830 nm) and very long PL lifetime (in the microsecond range). The pyramidal g‐QDs exhibit a quasi‐type II band structure with spatial separation of electron–hole wave function, suggesting an efficient exciton extraction and transport, which is consistent with theoretical calculations. These heterostructured g‐QDs are used as light harvesters to fabricate a photoelectrochemical cell, exhibiting a saturated photocurrent density as high as ≈5.5 mA cm −2 and good stability under 1 sun illumination (AM 1.5 G, 100 mW cm −2 ). These results are an important step toward using heterostructured pyramidal g‐QDs for prospective applications in solar technologies.