High-rate atomic layer deposition of Al2O3 for the surface passivation of Si solar cells

High-rate spatial atomic layer deposition (ALD) enables an industrially relevant deposition of high-quality aluminum oxide (Al2O3) films for the surface passivation of silicon solar cells. We demonstrate a homogeneous surface passivation at a deposition rate of ∼30 nm/min on 15.6×15.6 cm2 silicon wafers of 10 nm thick Al 2O3 layers deposited in a novel inline spatial ALD system. The effective surface recombination velocity on n-type Czochralski-grown (Cz) silicon wafers is shown to be virtually independent of injection level. Surface recombination velocities below 2.9 cm/s and an extremely low interface state density below 8×1010 eV-1cm-2 are achieved. We demonstrate that the novel inline spatial ALD system provides the means to integrate Al2O3 passivation layers into industrial solar cells.State of Lower SaxonyGerman Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU)/032505

IMPACT FORCES REDUCTION FOR HIGH- SPEED MICRO-ASSEMBLY

Abstract During the placement of components in micro-assembly, high impact forces occur. The current approach is to reduce these impact forces by coupling the gripper to the drive unit of the placement device with 5 DOF, wherein the gripper that contacts the component has a relatively low mass. To prevent the gripper from bouncing back at the end of the placement collision a force must be exerted between gripper and drive unit, which can significantly increase the impact forces. A solution has been found to realise an adequate force build-up between gripper and drive unit such that a rebounce of the gripper is prevented without significantly increasing the impact forces. This solution can be implemented relatively easily by placing a spring between gripper and drive unit combined with a force limiter