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In this work, a novel diode laser annealing was performed as a post-sulfurization heat treatment on pure-sulfide Cu 2 ZnSnS 4 thin film solar cells fabricated by sputtering deposition. The effect on both film quality and device performance after annealing at various laser doses was investigated. After receiving an ultra-fast laser scan treatment, the crystallinity of the CZTS film can be improved and the Cu/Zn disordering is reduced. The power conversion efficiency of the laser annealed device was boosted to 7.33%, compared with the reference cell efficiency of 6.72%. The major increase in the short circuit current is driving force of such improvement, from 18 mA/cm 2 to 19.31 mA/cm 2 after laser treatment. These results indicate that the quality of CZTS thin films and the device performance can be effectively improved by the diode laser annealing. [ABSTRACT FROM AUTHOR]

In this work, epitaxial Cu2ZnSnS4 (CZTS) films grown by magnetron sputtering were annealed by continuous wavelength diode laser as an alternative post-deposition heat treatment replacing conventional post-annealing within sulfur atmosphere to improve the film quality. Upon ultrafast millisecond diode laser annealing, improvement of crystallinity and reduction of Cu/Zn disordering were observed in the CZTS thin films. The results indicate that the diode laser treatment can enable fast, effective, and efficient annealing of CZTS thin films. [ABSTRACT FROM AUTHOR]

ABSTRACT Polycrystalline silicon films of 10 μm thickness are formed on glass in a single-step continuous wave diode laser crystallisation process, creating large crystal grains up to 1 mm wide and 10 mm long. Solar cells are formed on the layers by employing a rear point contacting scheme. Intermediate layers between the glass and the silicon are shown to heavily influence the cell characteristics. A stack of silicon oxide/silicon nitride/silicon oxide has produced the best cell efficiency so far of 8.4 % with open-circuit voltage of 557 mV. With simple optimisation of the contacting scheme, 10 % efficient cells are expected in the near future. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this work, magnetron sputtering was used to epitaxially grow Ge films on sapphire at low temperatures (400 °C–500 °C) and diode laser annealing was employed to improve the crystallinity of the Ge films. The deposition temperature might slightly influence the crystallinity of the Ge film through affecting the diffusion rate of Ge. After laser scans of milliseconds exposure time, significant defect density reduction and removal of polycrystalline portion are achieved. Magnetron sputtering combined with diode laser annealing offers a low-cost and fast method in fabricating high quality single crystalline Ge on sapphire which is potentially capable of large-scale production. [ABSTRACT FROM AUTHOR]

Single crystalline Ge-rich Si x Ge 1-x epitaxially grown on a Si substrate is attracting great attention for its potential in optical and electronic device applications. One method of achieving Si x Ge 1-x epitaxy is by aluminium-assisted crystallization although the challenge of controlling the Si content in the Si x Ge 1-x is limited by the furnace annealing process. Herein, we report the use of a diode laser to induce aluminium-assisted crystallization of Si x Ge 1-x on Si with minimal Si content in the Si x Ge 1-x layer. By replacing furnace heat treatment with laser treatment, the reaction time is shortened from minutes to milliseconds which can limit the amount of Si incorporation into the Si x Ge 1-x films. X-ray diffraction, Raman spectroscopy, transmission electron microscopy and X-ray spectroscopy analyses are conducted on the fabricated films revealing the achievement of Ge-rich Si x Ge 1-x on Si through laser-induced aluminium-assisted crystallization. The higher laser dose may slightly increase the Si content and improve the crystallinity of the Si x Ge 1-x films. • First use of laser to induce aluminium-assisted crystallization of Si x Ge 1-x on Si • The laser-induced method reduces the reaction time from minutes to milliseconds • Achievement of Ge-rich Si x Ge 1-x on Si by this laser-induced method • Higher laser dose may improve the crystallinity of Si x Ge 1-x films [ABSTRACT FROM AUTHOR]

In this work, epitaxial Ge films grown on Si by magnetron sputtering were annealed by diode laser as a replacement for conventional thermal annealing to reduce the threading dislocation density (TDD). After laser scans of millisecond exposure time, improvement of crystallinity and increase in tensile strain are observed in the Ge films. TDD of the Ge film is reduced by two orders of magnitude from 10 10 cm − 2 to 10 8 cm − 2 after only three laser scans. Diode laser annealing is a fast and low-cost method to effectively reduce TDD in epitaxial Ge films on Si. [ABSTRACT FROM AUTHOR]

A high density of intragrain defects in solid-phase crystallised Si thin films results in poor electronic properties and impedes their use for thin-film solar cell or thin-film transistor applications. This paper demonstrates that a high-power line-focus diode laser can eliminate intragrain defects (microtwins and dislocations) in polycrystalline Si films while maintaining the smooth defect-free surface. Improved electronic properties of ultra-thin polycrystalline Si thin films are thus achieved. To alleviate crack formation during diode laser annealing, a rapid-thermal pre-treatment at 800 °C for 60 s is introduced since it effectively relieves the tensile stress in the films and thus generates a more stable precursor material for subsequent laser annealing. The film thickness plays an important role in diode laser annealing. The films thinner than 100 nm show relatively smaller improvement due to the limited absorption of 808 nm laser radiation. [ABSTRACT FROM AUTHOR]