Active layer thickness

This strategy, although it can be used to achieve white emission, leads to a device fabrication process, which is tedious and where the emission color is sensitive to the operating voltage and device structure parameters such as active layer thickness and doping concentration. 

The results from OILEQUIL can be converted to an active layer thickness in several ways. First, the total thickness of the zone shown to contain product could be used. This would overestimate the thickness of the recoverable product layer, because oil at low saturations is immobile. Second, one could follow Van Dam (1967) in assuming a residual oil saturation of 20% (or another value appropriate to the soil and LNAPL involved) and pick out the thickness of the zone with greater than 20% product saturation from the OILEQUIL tabular output. In equation form,... 

Third, the total oil thickness (or thickness of saturated pores) determined by OILEQUIL could be converted to an active layer thickness using an assumed average oil saturation for the active product layer. One would divide the total oil thickness by the expected average saturation to get the actual thickness. Hence, a 2-cm total oil thickness would be equivalent to a 3-cm-thick active product layer with an average saturation of 66.7%. In equation form,... 

A series of LEDs with different active-layer thicknesses was grown by low-pressure MOCVD, with the structure given in the schematic in Fig. 6. The LEDs used were double-heterostructure, edge-emitting devices wherein p-type and n-type semiconductors sandwich an undoped, low-band-gap energy semiconductor (active layer). The p-n junction double-heterostructure is more efficient at trapping electrons and holes within the active layer for recombination, enhancing EL efficiency. 

Figure 9 PhotocuiTent from LED-photodiode integrated device (active-layer thickness is —500 nm. trench width is —20 p-m) for three cycles of N2 SO2 Nj at 1 atm each. A reproducible and stable enhancement of —30% was observed with respect to the N2 ambient. (From Ref. 14.)...

Figure 10 Photocurrent of the integrated device s photodiode (active layer thickness is -250 nm, ttench width is -15 (cm) in N2 (1 atm), vacuum (< 0.001 atm), and SO2 (1 atm) ambients upon excitation witli an external 633-nm 1 IcNe laser. (From Ref. 14.)...

FIGURE 3 Threshold current density as a function of active layer thickness. 

Fig. 3.23. Calculated and experimental J-V characteristics of the ITO/PEDOT PSS/MEH-PPV/Au diode at different temperatures with the active layer thickness of 65 nm. The symbols represent the experimental data, the dash-dot lines represent the conventional power law equation (3.42), while the solid curves represent the new theory equation (3.46) [44].

Chang JB, Subramanian V. (2006) Effect of active layer thickness on bias stress effect in pentacene thin-film transistors. Appl Phys Lett 88 233513. 

Moule AJ, Bonekamp JB, Meerholz K (2006) The effect of active layer thickness and composition on the performance of bulk-heterojunction solar cells. J Appl Phys... 

In this proceedings report we focus on the investigation of some peculiar, though quite important aspects, such as the effect on the OTFT sensor response of the active layer thickness and morphology as well as of the transistor channel length. 

Calculated optimized power conversion efficiency (filled squares) T p and individual layer thicknesses (open symbols) of PM-HJ cells under 1 sun of simulated solar illumination, as functions of the total active layer thickness... 

Working in collaboration with Reynolds, we have fabricated organic photovoltaic devices in which the active materials were assembled by using the LbL method [53]. In this work, the donor and hole transporting materials were the anionic CPEs PPE-SOs and PPE-EDOT-SO , whereas the acceptor and electron transport material was a cationic fullerene derivative, Cso-NHa (Scheme 14.13). The active layers were constructed atop an ITO substrate that was precoated with a PEDOT-PSS film (spin-coated). The PPE(—)/C6o—NHa bilayers were deposited through the LbL method, and the effect of active layer thickness on device performance was explored. Figure 14.20 shows a schematic... 

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