CIGS absorbers

Figure 7.7. Auger analysis of the CIGS absorber layer. [Reproduced with permission from Ref. 78(b). Copyright 2000 Elsevier.]...

To improve the junction property between CIGS absorber/Zn(0,S,OH)j and ZnO B window, Sang et al. [55] inserted an undoped thin CVD ZnO layer between the Zn(0,S,0H)a buffer and the ZnO B window. They observed an increase of both the Voc and FF, leading to a 30 x 30 cm2 submodule (aperture area = 864 cm2) with 12.93% efficiency. Finally, Olsen et al. [67] reached an efficiency of 13.95% (aperture area 0.13 cm2) for CIGS solar cells using a CVD ZnO buffer layer (see also Chaps. 4 and 9). 

Back contact CIGS Absorber p-type CdS n-type... 

HPLC has also been used to determine the residue levels of dinifroaniline herbicides. Pendimethalin was quantified by HPLC under the following conditions apparatus, Spectroflow 400 solvent delivery system. Model 430 gradient former, and Kratos Model 783 with UV absorbance detection at 239 nm column, Cig reversed-phase (25cmx 3.0-mm i.d.) temperature, 40 °C mobile phase, acetonitrile-water (7 3, v/v) flow rate, 1 mL min . ... 

Purification of the conjugates may be done by reverse phase HPLC separation. Dry the reaction solution under a nitrogen stream and reconstitute in a minimum volume of acetonitrile/water (1 1, v/v). Apply the sample to a 5 pm Cig-silica HPLC column (250 X 4.6 mm, Nucleosil). Elute with a gradient of water to acetonitrile at a flow rate of 1 ml/minute over a time course of 30 minutes. Free BNAH and BNAH-glycan derivatives can be monitored by absorbance at 275 nm. The conjugate peak also will be positive for carbohydrate by reaction with orcinol, which can be detected by spray after spotting a small eluted sample on a TLC plate. 

For solar cell applications, doping of CuInSe2 with Ga (CIGS) yields vacuum-evaporated absorber layers that produce solar cells with the highest... 

System (2) has been employed for the determination of cortisol and cortisone in urine [150]. Urine containing 6a-methyl prednisolone as an internal standard was applied to a Sep-Pak Cig cartridge, eluted with aqueous 90% acetonitrile, and the eluent analyzed by HPLC. The analytical column (25 cm x 4.6 mm) is packed with Altex Ultrasphere C s bonded silica (5 pm), and requires the use of a (5 cm x 5 mm) Hypercil ODS (5 pm) pre-column. The mobile phase used gradient elution with less than 100% acetonitrile, and detection is by UV absorbance at 260 nm. 

The separation and estimation of diloxanide furoate and metronidazole in solid dosage forms was reported by Bhoir et al., using packed column supercritical fluid chromatography [38], A JASCO Cig colunm (10 pm particle size, 25 cm x 4 mm) was used at 40°C, with an injection volume of 20 pL. The mobile phase consisted of 26% methanol in CO2 (flow rate of 2 mL/min), and operated at a pressure of 17.6 MPa. When detected on the basis of its ultraviolet absorbance at 230 nm, the retention time for the drug was 1.6 minutes. The linear region of the calibration graph was reported to be 20-70 pg/mL. 

There are a number of studies on the effects of the CD process on the surface of the CIS or CIGS. In many of these studies, the absorber surface was treated with partial CD solutions, in particular, ammonia or ammonia + Cd [12-19]. There are several reactions that occur during these treatments, and these will be discussed in general before specific results from the different studies are treated. 

Figure 8.3 Chromatograms obtained with different injectors. (A) Chromatogram obtained using a microvalve injector (B) chromatogram obtained using a conventional injector. Conditions column, Cig (250 mm X 1.5 mm I.D.) mobile phase, acetonitrile/water (90/10 v/v) flow rate, 0.1 ml/min injection volume, 1 ml detection, UV absorbance at 250 nm with 1-ml cell sample solvent acetonitrile. Peaks 1, benzene 2, naphthalene 3, biphenyl 4, fluorene 5, anthracene. (Reprinted from Ref. 1 with permission.)...

A thin i-ZnO (intrinsic ZnO) layer is often used as a buffer layer in CIS/CIGS solar cells, between the absorber part of the cell and the front TCO. The role of this resistive (buffer) layer is mainly to provoke suitable field-assisted hole collection at the contact interface, reducing, thus, the recombination rate at and near the ZnO/CIS or ZnO/CIGS interface (see also Chap. 9). 

Naturally-occurring humic-metal complexes have been isolated from estuarine systems and seawater using solid phase extraction (SPE) onto a Cig HPLC column to preconcentrate the sample (JO-12). Samples were subsequently eluted from the SPE colunm at a much higher concentration and injected onto another HPLC column and detected by UV absorbance and a metal-sensitive detector, such as atomic fluorescence spectroscopy. The concentration of metal-humic complexes in natural aquatic environments was then calculated. However, there was some evidence of competitive binding of the metal ion between the organic matter and free silanol groups in the stationary phase resulting in a loss of metal in the column and erroneously low metal values (10). 

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