This sacrificial layer approach allows for high pattern fidelity and stability, and it leads directly to stable, GSK690693 clinical trial micrometer-thick, and contamination-free TNP patterns for developing the SS-DSSC array for miniature high-voltage applications. Methods Fabrication of TNP patterns In preparing photoanodes connected in series for a high-voltage Tozasertib purchase DSSC array, micropatterns of
the TNP were constructed on a pre-patterned fluorine-doped tin oxide (FTO) glass. An array of 20 FTO electrodes, where each electrode has a width of 500 μm and a gap of 500 μm between two adjacent electrodes, was prepared using photolithography and a dry etching process. A glass substrate with pre-patterned FTO was cleaned with acetone, deionized water, and ethanol in sequence and dried with nitrogen flow. The cleaned substrate was then dried at 90°C in a vacuum oven for 10 min to remove any residual water and subsequently treated with ultraviolet Milciclib concentration ozone for 5 min. In order to improve the adhesion and the mechanical strength of the TNP layer [13], the treated FTO glass was soaked in an aqueous solution of 40 mM TiCl4 at 70°C for 30 min. The FTO glass was then cleaned in the same way described above. Figure 1 shows the schematic diagram illustrating the fabrication
of a patterned TNP layer on the FTO glass. The entire fabrication processes of patterning TNP are as follows: An elastomer stamp with patterns, complementary to desired TNP patterns, was made of poly-(dimethylsiloxane) (PDMS). For fabricating complementary patterns of a sacrificial Farnesyltransferase layer (SL) on the FTO glass, a fluorous polymer (3 M Novec™ EGC-1700, 3 M Novec, Manassas, VA, USA) dissolved in a highly fluorous solvent (3 M Novec™ HFE-7100) was dip-coated on the prepared PDMS stamp. Figure 1a shows the transfer printing process of the complementary patterns of the SL on the PDMS stamp onto the FTO glass. Note that no
additional pressure or heat is required during transfer printing due to the lower surface energy of the PDMS stamp than that of the FTO glass [14]. Ti-Nanoxide T (Solaronix SA, Aubonne, VD, Switzerland) paste was subsequently prepared on the SL-patterned FTO glass to form a TNP layer using a doctor-blading technique, as shown in Figure 1b. The TNP film was soft-cured at 50°C for 3 min for the fixation of the TNPs to ensure stability during the following lift-off process. In the soft-cure treatment, the duration of heating plays a critical role in patterning the TNP layer of a few micrometers thick; the TNP layer should be sufficiently soft for the application of the lift-off process but structurally strong enough to prevent the collapse of the TNP stacks during the lift-off process.