Yeu-Long Jiang

In this work, hydrogenated amorphous silicon carbide (a-SiC_x:H) and hydrogenated amorphous silicon oxide (a-SiO_x:H) films with similar optical bandgaps (E_g), refractive indices (n), and extinction coefficients (k) were fabricated using pulse-wave modulation (PWM) plasma technology by controlling the plasma turn-on to turn-off time ratio (t_on/t_off). These films were placed at the 1/5 position of the p/i and i/n interfaces of hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells to investigate their influence on solar cell performance. The experimental results confirmed that the deviations in E_g, n, and k were controlled to within 0.2%, 1.4%, and 4.1%, respectively. Under these conditions, placing a-SiC_x:H and a-SiO_x:H films at the p/i and i/n interfaces successfully increased the open-circuit voltage (V_oc). However, this also led to a decrease in the short-circuit current due to valence band (ΔE_v) or conduction band (ΔE_c) offsets. The reduction in cell fill factor (FF) and efficiency (η) caused by placing a-SiC_x:H and a-SiO_x:H films at the p/i interface was greater than that caused by placing them at the i/n interface. Placing the a-SiC_x:H film at the p/i interface significantly improved the V_oc to 0.8998 V. Due to the n-type doping effect of oxygen atoms, the a-SiO_x:H film exhibited the lowest FF of 43.99% and η of 4.850% at the p/i interface; however, when placed at the i/n interface, it yielded an FF of 67.38% and an η of 7.43%, which are comparable to the standard cell. Appropriately placing the a-SiC_x:H film at the p/i interface and the slightly n-type a-SiO_x:H film at the i/n interface can effectively improve the V_oc, FF, and η of p-i-n solar cells.

In this work, hydrogenated amorphous silicon carbide (a-SiCx​:H) and hydrogenated amorphous silicon oxide (a-SiOx​:H) films with similar optical bandgaps (Eg​), refractive indices (n), and extinction coefficients (k) were fabricated using pulse-wave modulation plasma technology by controlling the plasma turn-on and turn-off time ratio (ton​​/toff​). These films were placed at the 1/4 position of the p/i and i/n interfaces of hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells to investigate their influence on solar cell performance. Experimental results showed that when deviations in Eg​, n, and k were less than 0.2%, 1.4%, and 4.1%, respectively, placing a-SiCx​:H and a-SiOx​:H films at the p/i and i/n interfaces increased the open-circuit voltage (Voc​​) and decreased the short-circuit current due to valence band (ΔEv​) or conduction band (ΔEc​​) offsets. The reduction in cell fill factor (FF) and efficiency (η) caused by placing a-SiCx​:H and a-SiOx​:H films at the p/i interface was greater than that caused by placing them at the i/n interface. Placing the a-SiCx​:H film at the p/i interface significantly improved the Voc​​. Due to the n-type doping effect of oxygen atoms, the a-SiOx​:H film exhibited the lowest FF and η at the p/i interface; however, when placed at the i/n interface, it yielded FF and η values second only to the a-Si:H standard reference cell. Appropriately placing the a-SiCx​:H film at the p/i interface and the slightly n-type a-SiOx​:H film at the i/n interface can effectively improve the Voc​​, FF, and η of p-i-n solar cells.

In this study, inorganic silicon oxide (SiO_x)/organic silicon (SiC_xH_y) stacked layers were deposited by a radio frequency inductively coupled plasma chemical vapor deposition system as a gas diffusion barrier for organic light-emitting diodes (OLEDs). The effects of thicknesses of SiO_x and SiC_xH_y layers on the water vapor transmission rate (WVTR) and residual stress were investigated to evaluate the encapsulation capability. The experimental results showed that the lowest WVTR and residual stress were obtained when the thicknesses of SiO_x and SiC_xH_y were 300 and 30 nm, respectively. Finally, different numbers of stacked pairs of SiO_x/SiC_xH_y were applied to OLED encapsulation. The OLED encapsulated with the six-pair SiO_x/SiC_xH_y exhibited a low turn-on voltage and low series resistance, and device lifetime increased from 7 h to more than 2000 h.

Nano-porous polysilicon high-temperature resistant solar absorption films were prepared by a thin layer of silver nanoparticles catalytic chemical etching. The polysilicon films with average tiny grain size of approximately 30 nm were obtained by high-temperature 800 °C furnace annealing of hydrogenated amorphous silicon films that were deposited on stainless substrate by plasma-enhanced chemical vapor deposition. The uniformly distributed 19 nm sized silver nanoparticles with 8 nm interspacing deposited on poly-Si film, were controlled by thin 4 nm thickness and very slow deposition rate 0.4 nm/min of thermal evaporation. Small silver nanoparticles with short spacing catalyzes the detouring etching process inducing the nano-porous textured surface with deep threaded pores. The etching follows the trail of the grain boundaries, and takes a highly curved thread like structure. The etching stops after reaching a depth of around 1100 nm, and the rest of the bulk thickness of the film remains mostly unaffected. The structure consists of three crystal orientations (111), (220), and (331) close to the surface. This crystalline nature diminishes gradually in the bulk of the film. High absorbance of 95% was obtained due to efficient light-trapping. Hence, preparation of nano-porous polysilicon films by this simple method can effectively increase solar absorption for the receiver of the solar thermal electricity Stirling Engine.

This paper develops fifth-generation-sized silicon thin-film tandem photovoltaic (PV) modules with animated images. Front PV cell stripes are created using a laser scribing technique, and specially edited and shifted images are printed onto the back glass. After encapsulating the front PV module with the back glass, the animated image effect can then be clearly seen from various positions. The PV module that can display three images has a stabilized power output of 87 W. The remarkable features of this module such as its animated image display, semitransparency, and acceptable power loss give it great potential for use in building-integrated photovoltaics. This paper could help improve the aesthetic appearance of PV modules, which may increase users’ or architects’ willingness to install PV modules on buildings.

In this study, the antimicrobial property and food package capability of polymethylpentene (PMP) substrate with silicon oxdie (SiO_x) and organic silicon (SiC_xH_y) stacked layers deposited by an inductively coupled plasma chemical vapor deposition system were investigated. The experimental results show that the stacked pair number of SiO_x/SiC_xH_y on PMP is limited to three pairs, beyond which the films will crack and cause package failure. The three-pair SiO_x/SiC_xH_y on PMP shows a low water vapor transmission rate of 0.57 g/m²/day and a high water contact angle of 102°. Three-pair thin-film coated PMP demonstrates no microbe adhesion and exhibits antibacterial properties within 24 h. Food shelf life testing performed at 28 °C and 80% humidity reports that the three-pair thin-film coated PMP can enhance the food shelf-life to 120 h. The results indicate that the silicon-based thin film may be a promising material for antibacterial food packaging applications to extend the shelf-life of food products.

In this study, metal films are fabricated by using an in-line reactive direct current magnetron sputtering system. The aluminum–titanium (AlTi) back contacts are prepared by changing the pressure from 10 mTorr to 25 mTorr. The optical, electrical and structural properties of the metal back contacts are investigated. The solar cells with the AlTi had lower contact resistance than those with the silver (Ag) back contact, resulting in a higher fill factor. The AlTi contact can achieve a solar cell conversion efficiency as high as that obtained from the Ag contact. These findings encourage the potential adoption of AlTi films as an alternative back contact to silver for silicon thin-film solar cells.