Structural, optical, and electrical properties of PbSe nanocrystal solids treated thermally or with simple amines

被引:379
作者
Law, Matt [1 ]
Luther, Joseph M. [1 ]
Song, Oing [1 ]
Hughes, Barbara K. [1 ]
Perkins, Craig L. [1 ]
Nozik, Arthur J. [1 ]
机构
[1] Natl Renewable Energy Lab, Golden, CO 80401 USA
关键词
D O I
10.1021/ja800040c
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
We describe the structural, optical, and electrical properties of films of spin-cast, oleate-capped PbSe nanocrystals that are treated thermally or chemically in solutions of hydrazine, methylamine, or pyridine to produce electronically coupled nanocrystal solids. Postdeposition heat treatments trigger nanocrystal sintering at similar to 200 degrees C, before a substantial fraction of the oleate capping group evaporates or pyrolyzes. The sintered nanocrystal films have a large hole density and are highly conductive. Most of the amine treatments preserve the size of the nanocrystals and remove much of the oleate, decreasing the separation between nanocrystals and yielding conductive films. X-ray scattering, X-ray photoelectron and optical spectroscopy, electron microscopy, and field-effect transistor electrical measurements are used to compare the impact of these chemical treatments. We find that the concentration of amines adsorbed to the NC films is very low in all cases. Treatments in hydrazine in acetonitrile remove only 2-7% of the oleate yet result in high-mobility n-type transistors. In contrast, ethanol-based hydrazine treatments remove 85-90% of the original oleate load. Treatments in pure ethanol strip 20% of the oleate and create conductive p-type transistors. Methylamine- and pyridine-treated films are also p-type. These chemically treated films oxidize rapidly in air to yield, after short air exposures, highly conductive p-type nanocrystal solids. Our results aid in the rational development of solar cells based on colloidal nanocrystal films.
引用
收藏
页码:5974 / 5985
页数:12
相关论文
共 53 条
[1]  
Alemozafar AR, 2005, J PHYS CHEM B, V109, P11307, DOI [10.1021/jp050338l, 10.1021/jp0503381]
[2]   Water dissociation on Ru(001): An activated process [J].
Andersson, K ;
Nikitin, A ;
Pettersson, LGM ;
Nilsson, A ;
Ogasawara, H .
PHYSICAL REVIEW LETTERS, 2004, 93 (19) :196101-1
[3]   Electroluminescence in thin solid films of closely packed CdS nanocrystals [J].
Artemyev, MV ;
Sperling, V ;
Woggon, U .
JOURNAL OF APPLIED PHYSICS, 1997, 81 (10) :6975-6977
[4]   Fabrication and characterization of red-emitting electroluminescent devices based on thiol-stabilized semiconductor nanocrystals [J].
Bertoni, Cristina ;
Gallardo, Diego ;
Dunn, Steve ;
Gaponik, Nikolai ;
Eychmueller, Alexander .
APPLIED PHYSICS LETTERS, 2007, 90 (03)
[5]   THE ADSORPTION AND DECOMPOSITION OF METHYLAMINE ON PD(111) [J].
CHEN, JJ ;
WINOGRAD, N .
SURFACE SCIENCE, 1995, 326 (03) :285-300
[6]   Electroluminescence from single monolayers of nanocrystals in molecular organic devices [J].
Coe, S ;
Woo, WK ;
Bawendi, M ;
Bulovic, V .
NATURE, 2002, 420 (6917) :800-803
[7]  
COLVIN VL, 1994, NATURE, V370, P354, DOI 10.1038/370354a0
[8]   Systematic XPS studies of metal oxides, hydroxides and peroxides [J].
Dupin, JC ;
Gonbeau, D ;
Vinatier, P ;
Levasseur, A .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2000, 2 (06) :1319-1324
[9]   Highly efficient multiple exciton generation in colloidal PbSe and PbS quantum dots [J].
Ellingson, RJ ;
Beard, MC ;
Johnson, JC ;
Yu, PR ;
Micic, OI ;
Nozik, AJ ;
Shabaev, A ;
Efros, AL .
NANO LETTERS, 2005, 5 (05) :865-871
[10]   Doping semiconductor nanocrystals [J].
Erwin, SC ;
Zu, LJ ;
Haftel, MI ;
Efros, AL ;
Kennedy, TA ;
Norris, DJ .
NATURE, 2005, 436 (7047) :91-94