Critical Evaluation of Organic Thin-Film Transistor Models

Thin-film transistors (TFTs) represent a wide-spread tool to determine the charge-carrier mobility of materials. Mobilities and further transistor parameters like contact resistances are commonly extracted from the electrical characteristics. However, the trust in such extracted parameters is limited, because their values depend on the extraction technique and on the underlying transistor model. We propose a technique to establish whether a chosen model is adequate to represent the transistor operation. This two-step technique analyzes the electrical measurements of a series of TFTs with different channel lengths. The first step extracts the parameters for each individual transistor by fitting the full output and transfer characteristics to the transistor model. The second step checks whether the channel-length dependence of the extracted parameters is consistent with the model. We demonstrate the merit of the technique for distinct sets of organic TFTs that differ in the semiconductor, the contacts, and the geometry. Independent of the transistor set, our technique consistently reveals that state-of-the-art transistor models fail to reproduce the correct channel-length dependence. Our technique suggests that contemporary transistor models require improvements in terms of charge-carrier-density dependence of the mobility and/or the consideration of uncompensated charges in the transistor channel.Comment: 20 pages, 10 figure

Dollars and Sense of Alfalfa: Marketing Your High Yield, High Quality Alfalfa at High Prices

It seems every farmer wants to be in the commercial hay business--growing hay for the cash market. Have you ever stopped to think about the amount of hay that would be produced if everyone who talked about producing hay actually produced hay

Comparison of Hiring Strategies of Orthodontic Private Practitioners

COMPARISON OF HIRING STRATEGIES OF ORTHODONTIC PRIVATE PRACTITIONERS By Steven C. Petritz, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University Virginia Commonwealth University, 2018 Thesis Director: Bhavna Shroff, D.D.S., M.Dent.Sc., M.P.A. Virginia Commonwealth University Department of Orthodontics Program Director Purpose: Evaluate factors that influence hiring outcomes of clinical and non-clinical staff in orthodontic private practices. Methods: Orthodontists (n=1968) were surveyed regarding their hiring methods and outcomes. Responses were summarized using descriptive statistics. Chi-square tests were used to compare between hiring strategies and outcomes. Results: Survey response rate was 23% (n = 452 responses). 65% received 1-10 applicants and 54% utilized online job sites. Online job sites was associated with increased number of applicants (p\u3c0.0001) and number of days to fill the position (p\u3c0.0001). Forty-seven percent of respondents used the internet to screen candidates. Sixty-two percent of respondents hired based on personality. Fifty-seven percent of respondents plan to use employee referrals for future hiring needs. Conclusion: Online job sites accounted for the majority of the most recent hires. Orthodontists indicated that their future preference to be employee referrals. Social and professional relationships may lead to a more efficient hiring process

You Can Make Money Producing and Marketing Alfalfa in the 80\u27s

We are today, as we were during most of the 70\u27s, concerned with the future of the forage enterprise and the livestock species that depend on it. Will they survive an environment in which the emphasis is on grain exports? Will they survive in an environment in which consumers are not able (but hopefully willing) to pay prices for red meats which are profitable for all segments of the livestock industry? Will they survive in the 80\u27s when real interest rates will be relatively high