Low temperature growth of highly conducting boron doped nc-Si thin films on flexible substrates

• Main Authors: Das, Debajyoti, Patra, Chandralina
• Format: Conference Proceeding
• Language: English
• Subjects: Boron; Crystal structure; Crystallinity; Dilution; Electrical resistivity; Electronic devices; Electronic systems; High temperature; Inductively coupled plasma; Low temperature; Photographic plates; Photovoltaic cells; Power management; Power sources; Room temperature; Silicon films; Silicon substrates; Solar cells; Thin films
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0009019

In order to popularize the next-generation of low-cost, flexible, disposable and portable electronic systems, integration of power sources on flexible substrates appears essential, which in turn needs a low temperature growth process. Silicon is the work-horse of the semiconductor industry and is a common requirement of the electronic as well as power devices, e.g., photovoltaic solar cells. Normally, crystallinity in Si from the SiH4 plasma is accompanied by a high temperature growth from highly H2-diluted plasma ensemble which leads to the inevitable lower growth rate. The novelty of the present work is the successful growth of boron doped nc-Si thin films possessing high crystallinity ∼76 vol.% with moderately high electrical conductivity ∼10−1 S cm−1 on flexible photographic plates at low substrate temperature ∼100 °C, using planar inductively coupled plasma CVD of B2H6 (1% in H2) mixed with SiH4, without any deliberate H2 dilution. Even the room temperature (∼30 °C) grown B-doped nc-Si film on flexible substrate demonstrates electrical conductivity ∼10−3 S cm−1 and a moderate crystallinity ∼69 vol%, which is remarkable, the first report of its kind, and highly promising for applications in nc-Si thin film flexible solar cells.