Dip‐Coated Gold Nanoparticle Electrodes for Aqueous‐Solution‐Processed Large‐Area Solar Cells

Abstract

gold NPs monolayer was introduced on the interface between the water and n-hexane and then dip-coating technique was adopted to generate a large area gold NPs fi lm ( Scheme 1 ). Fabricating a 2D gold fi lm by this water/oil method was proposed in past work. [ 24,25 ] However, to the best of our knowledge, this is the fi rst time to investigate it as an electrode for solar cells. It is worth noting that when 15 nm and 35 nm gold NPs were used to generate the multilayer gold fi lms, thermal treatment was required to avoid the dissolution of gold fi lm by subsequent dip-coating process. Nevertheless, in the case of 60nm gold NPs, stewing the fi lm in air for a while was enough for the next layer dip-coating. We attribute this phenomenon to the different solubility of gold NPs with varying size. Relatively, the smaller NPs have more citrate ions capped than the bigger NPs and possess better solubility. Upon annealing, the gold NPs fi lm would experience processes of melting, interparticle coalescence and dewetting, [ 26 ] thus making it more hydrophobic. As for the 60 nm gold NPs, with less citrate ions capping, lower solubility and larger size made the fi lm difficult to dissolve in water after stewing in the air for a while.The electric resistance of gold fi lms with different NP sizes and different dip-coated layers (1, 2, 3, and 4) was investigated previously. Figure 1 shows the electric resistance of the gold NPs fi lms measured by the four-point probe meter. Detailed information is shown in Table 1 . The electric resistance decreases dramatically when the layer number of gold fi lms increases. In the case of the 60 nm gold NPs, the electric resistance values are 897 Ω/ٗ, 4.5 Ω/ٗ, 2 Ω/ٗ and 1.3 Ω/ٗ respectively for 1 to 4 layers. To illustrate this relationship, TEM and scanning electron microscopy (SEM) characterizations ( Figure 2 ) are conducted. For one layer, the gold nanoparticles are assembled incompactly with inhomogeneously interparticle distances, which are adverse for electron transfer. Due to the inhomogeneous arrangement of NPs in the monolayer, the R s values show slight fl uctuation when different positions of the fi lms are measured. As more layers are dip-coated, the interparticle distances become much smaller, which is in accordance with the decrease in R s . Moreover, the R s values measured in different positions of the fi lms become more stable. The gold fi lms with three layers and four layers show similar R s values, both of which are very small. As shown

Solution processed CdTe/CdSe nanocrystal solar cells with more than 5.5% efficiency by using an inverted device structure

“…[1][2][3] To date, III-V NCs including PbS, 4 PbSe 5 and PbS x Se 1Àx (ref. On the other hand, solar cells based on sintering NCs such as CuInS 2 , 7 CuInSe 2 8 and CdTe [9][10][11][12][13][14][15] have also been investigated and good device performances have been obtained. On the other hand, solar cells based on sintering NCs such as CuInS 2 , 7 CuInSe 2 8 and CdTe [9][10][11][12][13][14][15] have also been investigated and good device performances have been obtained.…”

Effect of amino, hydroxyl, and carboxyl terminal groups of alkyl chains of self‐assembled monolayers on the adsorption pattern of gold nanoparticles

“…The interfacial interactions of gold nanoparticles (AuNPs) and control of these interactions have been extensively studied because of the utility of AuNPs in various practical applications, including energy harvesting, medical engineering, medicine delivery, and biosensors . Solar‐cell electrodes covered with AuNP films exhibit relatively high incident‐photon‐to‐photocurrent efficiency rates and can be used to increase the power conversion efficiency of solar cells . AuNPs are also useful as biomarkers in live cells .…”

“…4 Solar-cell electrodes covered with AuNP films exhibit relatively high incident-photon-to-photocurrent efficiency rates and can be used to increase the power conversion efficiency of solar cells. 5 AuNPs are also useful as biomarkers in live cells. 6 AuNPs are preferentially adsorbed by the surface of cancer cells rather than by noncancer cells.…”

Recent Progress on Solution-Processed CdTe Nanocrystals Solar Cells

“…Following this, Yang [72] and other groups [73] made a number of attempts to improve the device performance. It is worth mentioning that dip-coating gold nanoparticle (NP) films as the back electrode can be used for large-area aqueous-solution-processed HSCs [74]. Subsequently, Yang et al [75] developed a new water-soluble poly(2,5-thienylene vinylene) (PWTV).…”