We have demonstrated a top-illuminated organic photovoltaic device with a thick Ag anode and a thin Ag cathode capped with an α-naphthylphenylbiphenyl diamine (NPB) thin film. The surface of the Ag anode was oxidized by UV–ozone which improved the carrier collection and reduced the exciton quenching. Compared with the control device with an indium tin oxide anode, a 15.59 times reduction in the serial resistance and a 1.72 times increase in the shunt resistance were observed with a fill factor of 0.61 in such a device. The NPB capping layer not only improved the light transmission from the semitransparent cathode, but also hindered the formation of Ag island growth and thereby improved the device stability.

In this paper, we have employed different shadow masks attached on top of organic photovoltaic (OPV) devices to study the optical effects of the former on the short circuit current (J SC ). To rule out possible lateral electrical conduction and simplify the optical effects inside the device, a small-molecular heterojunction OPV device with a clear donor/acceptor interface was employed with a hole extraction layer exhibiting high resistance intentionally. Careful calibration with a shadow mask was employed. By attaching two layers of opaque masks in combination with a suitable holder design to shield the light from the edges and backside, the value of J SC approached that of the dark current, even under 1-sun radiation. With different illumination areas, we found that the photons illuminating the non-active region of the device contributed to 40% of the J SC by optical effect within the width of about 1 mm around the active region. When illuminating the non-active area with 12 mm to the active area, a 5.6 times improvement in the J SC was observed when the incident angle was 751. With the introduction of a microstructured film onto the OPV device and an increase in the reflection from the non-active region, a 15% enhancement of the J SC compared to the control device was achieved.

Palladium (Pd) membranes for hydrogen separation were deposited on modified porous stainless steel (PSS) tubes using the electroless plating technique. This study explores the hydrogen permeance influenced by the effect of reducing the thickness of the Pd membrane using different sizes of Al 2 O 3 particles, 10 and 1 mm, to modify the pores on the PSS surface. The pore size on the surface of the PSS tubes modified with 10 mm Al 2 O 3 particles decreased from 10 $ 20 mm to less than 5 mm, while the surface of the PSS, modified by 1 mm Al 2 O 3 , was very dense and smooth. Generally, the supporting tubes with smaller pore size on the surface give thinner Pd membrane. The minimum thickness of a dense Pd membrane decreased from 35.1 to 16.2 mm when using 1 mm Al 2 O 3 particles to modify the PSS tubes, but the maximum hydrogen permeance was enhanced from 15.3 to 34.7 m 3 /m 2 h atm 0.5 at 500 C by using 10 mm Al 2 O 3 particles. This evidence demonstrated the hydrogen permeance has a trade-off between the porosity (effective passages) and thickness of the Pd membranes since both are influenced by the Al 2 O 3 particle size used in the surface modification. These results suggested a promising and simple approach to produce a Pd membrane with high hydrogen permeance.

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