Electrical properties of aerosol printed contacts

The influence of printing height of the seed layer on the front side metallization was investigated. Therefore, solar cells were metalized using the aerosol printing technique and the seed layer ink for the metallization of solar cells (SISC) developed at Fraunhofer ISE. The single lines were deposited one over each other increasing the amount of ink per contact area. After contact firing and light-induced plating, the contact resistance was determined using the transfer-length model (TLM). The finger geometry was determined from cross sectional measurements and the conductivity from 4-probe measurements. In order to analyse the relationship between the amount of printed ink and the contact quality, the metal contacts were removed in an HNO3/HF etching step and the metal semiconductor interface was analyzed via SEM images. It could be shown that a very thin single-printed seed layer leads to the best contact properties