@article {42575, title = {Solution-processed inorganic bulk nano-heterojunctions and their application to solar cells}, journal = {Nature Photonics}, volume = {6}, year = {2012}, month = {JUL}, pages = {529{\textendash}534}, abstract = {

In the last decade, solution-processed quantum dot/nanocrystal solar cells have emerged as a very promising technology for third-generation thin-film photovoltaics because of their low cost and high energy-harnessing potential. Quantum dot solar cell architectures developed to date have relied on the use of bulk-like thin films of colloidal quantum dots. Here, we introduce the bulk nano-heterojunction concept for inorganic solution-processed semiconductors. This platform can be readily implemented by mixing different semiconductor nanocrystals in solution and allows for the development of optoelectronic nanocomposite materials with tailored optoelectronic properties. We present bulk nano-heterojunction solar cells based on n-type Bi2S3 nanocrystals and p-type PbS quantum dots, which demonstrate a more than a threefold improvement in device performance compared to their bilayer analogue, as a result of suppressed recombination.

}, doi = {10.1038/nphoton.2012.139}, author = {Rath, Arup Kumar and Bernechea, Maria and Martinez, Luis and Pelayo Garcia de Arquer, F. and Osmond, Johann and Konstantatos, Gerasimos} } @article {42573, title = {Heterovalent cation substitutional doping for quantum dot homojunctions}, journal = {Nature Communications}, volume = {4}, year = {2013}, month = {DEC}, pages = {Article number: 2981}, abstract = {

Colloidal quantum dots have emerged as a material platform for low-cost high-performance optoelectronics. At the heart of optoelectronic devices lies the formation of a junction, which requires the intimate contact of n-type and p-type semiconductors. Doping in bulk semiconductors has been largely deployed for many decades, yet electronically active doping in quantum dots has remained a challenge and the demonstration of robust functional optoelectronic devices had thus far been elusive. Here we report an optoelectronic device, a quantum dot homojunction solar cell, based on heterovalent cation substitution. We used PbS quantum dots as a reference material, which is a p-type semiconductor, and we employed Bi-doping to transform it into an n-type semiconductor. We then combined the two layers into a homojunction device operating as a solar cell robustly under ambient air conditions with power conversion efficiency of 2.7\%.

}, doi = {10.1038/ncomms3981}, author = {Stavrinadis, Alexandros and Rath, Arup Kumar and Pelayo Garcia de Arquer, F. and Diedenhofen, Silke L. and Magen, Cesar and Martinez, Luis and So, David and Konstantatos, Gerasimos} } @article { ISI:000339661100021, title = {Remote trap passivation in colloidal quantum dot bulk nano-heterojunctions and its effect in solution-processed solar cells}, journal = {Advanced Materials}, volume = {26}, number = {27}, year = {2014}, month = {JUL}, pages = {4741+}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

More-efficient charge collection and suppressed trap recombination in colloidal quantum dot (CQD) solar cells is achieved by means of a bulk nano-heterojunction (BNH) structure, in which p-type and n-type materials are blended on the nanometer scale. The improved performance of the BNH devices, compared with that of bilayer devices, is displayed in higher photocurrents and higher open-circuit voltages (resulting from a trap passivation mechanism).

}, issn = {0935-9648}, doi = {10.1002/adma.201400297}, author = {Rath, Arup Kumar and Pelayo Garcia de Arquer, F. and Stavrinadis, Alexandros and Lasanta, Tania and Bernechea, Maria and Diedenhofen, Silke L. and Konstantatos, Gerasimos} }