Monolithically integrated optical interference and absorption filters on thin film amorphous silicon photosensors for biological detection

AbstractWe present the first thin film transistors (TFTs) incorporating a low hydrogen content (5 - 9 at.-%) amorphous silicon (a-Si:H) layer deposited by the Hot-Wire Chemical Vapor Deposition (HWCVD) technique. This demonstrates the possibility of utilizing this material in devices. The deposition rate by Hot-Wire CVD is an order of magnitude higher than by Plasma Enhanced CVD. The switching ratio for TFTs based on HWCVD a-Si:H is better than 5 orders of magnitude. The field-effect mobility as determined from the saturation regime of the transfer characteristics is still quite poor. The interface with the gate dielectric needs further optimization. Current crowding effects, however, could be completely eliminated by a H2 plasma treatment of the HW-deposited intrinsic layer. In contrast to the PECVD reference device, the HWCVD device appears to be almost unsensitive to bias voltage stressing. This shows that HW-deposited material might be an approach to much more stable devices.

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Development of n-μc-SiOx:H as cost effective back reflector and its application to thin film amorphous silicon solar cells

Solar Energy ◽

10.1016/j.solener.2013.09.021 ◽

2013 ◽

Vol 97 ◽

pp. 591-595 ◽

Cited By ~ 12

Author(s):

C. Banerjee ◽

T. Srikanth ◽

U. Basavaraju ◽

R.M. Tomy ◽

M.G. Sreenivasan ◽

...

Keyword(s):

Thin Film ◽

Solar Cells ◽

Amorphous Silicon ◽

Cost Effective ◽

Silicon Solar Cells ◽

Back Reflector

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Hydrogenated Nanocrystalline Silicon Thin Film Transistor Array for X-ray Detector Application

MRS Proceedings ◽

10.1557/proc-1066-a16-07 ◽

2008 ◽

Vol 1066 ◽

Author(s):

Kyung-Wook Shin ◽

Mohammad R. Esmaeili-Rad ◽

Andrei Sazonov ◽

Arokia Nathan

Keyword(s):

Thin Film ◽

Amorphous Silicon ◽

Threshold Voltage ◽

Hydrogenated Amorphous Silicon ◽

Nanocrystalline Silicon ◽

Amorphous Selenium ◽

Breakdown Field ◽

Storage Capacitor ◽

X Ray ◽

Hydrogenated Amorphous

ABSTRACTHydrogenated nanocrystalline silicon (nc-Si:H) has strong potential to replace the hydrogenated amorphous silicon (a-Si:H) in thin film transistors (TFTs) due to its compatibility with the current industrial a-Si:H processes, and its better threshold voltage stability [1]. In this paper, we present an experimental TFT array backplane for direct conversion X-ray detector, using inverted staggered bottom gate nc-Si:H TFT as switching element. The TFTs employed a nc-Si:H/a-Si:H bilayer as the channel layer and hydrogenated amorphous silicon nitride (a-SiNx) as the gate dielectric; both layers deposited by plasma enhanced chemical vapor deposition (PECVD) at 280°C. Each pixel consists of a switching TFT, a charge storage capacitor (Cpx), and a mushroom electrode which serves as the bottom contact for X-ray detector such as amorphous selenium photoconductor. The chemical composition of the a-SiNx was studied by Fourier transform infrared spectroscopy. Current-voltage measurements of the a-SiNx film demonstrate that a breakdown field of 4.3 MV/cm.. TFTs in the array exhibits a field effect mobility (μEF) of 0.15 cm2/V·s, a threshold voltage (VTh) of 5.71 V, and a subthreshold leakage current (Isub) of 10−10 A. The fabrication sequence and TFT characteristics will be discussed in details.

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