, materials scientists at Rice University have found it to be a promising candidate for “Nano-electronic applications” that require stability . Now to be clear this is not the common element phosphorus. Rather it is a “two-dimensional phosphorus, [made] through exfoliation from black phosphorus” . Black phosphorus is believed to be the most stable form of phosphorus. It is created when phosphorus is put at “higher temperatures about 590 °C and higher pressures” or when phosphorus is combined with a “catalyst at ordinary pressures and a temperature of about 200°C” .
Researchers at Rice University compared 2-dimensional phosphorus with other 2-dimensional metal dichalcogenides like molybdenum disulfide because of their inherent conductive properties (metals are natural conductors). Issues have arisen, however, where these other compounds bond-the point where the elements meet (point defect). A disturbance is created in the flow of the current. In doped silicon, this doesn’t occur because the negative and positive silicon work together to fill in these gaps therefore eliminating a disruption in flow. When there are “multiple point defects or grain boundaries-where the sheets of a 2-D material merge at angles” the device is no longer useful .
Advantages of Phosphorus
2-dimensional phosphorus does not exhibit the same issues at the point defects that other materials tested experienced. According to calculations done by theoretical physicist Boris Yakobson and his colleagues at Rice University, the point where 2-dimensional phosphorus point defects or grain boundaries exist, the materials semiconducting properties remain stable. This transpires at the point defects because “atoms jut out of the matrix, this complexity gives rise to more variations among defects” . Also, 2-D phosphorus bonds with itself, this therefore eliminates the recombining of electrons that occurs between hetero-elemental bonds. 2-dimensional phosphorus is very similar to 3-dimensional silicon because they both don’t have issues with band-gap changes at ground boundaries. The key difference however between the two is that 3-dimensional silicon can change its properties from positive to negative at the point defects, and this does not occur in phosphorus. Another benefit of 2-dimensional phosphorus is that phosphorus exists in abundance on Earth, and the black phosphorus is relatively easy to make. No production worthy semiconductor equipment available yet for this material.
Future of Phosphorus Semiconductors
The researchers at Rice University believe that 2-dimensional phosphorus semiconductors could potentially be used to harvest sunlight in solar cells because their band-gap matches well with the solar spectrum. Due to the way this new phosphorus responds at the point defects, the materials performance would not deteriorate as it has with other materials tested . This is great news for the solar industry that is constantly looking for new ways to improve their products and make them more durable and efficient.
2-dimensional phosphorus has already been tested in “high-performing electronics, and has already shown it can be a better transistor than 2-D metal dichalcogenides” .
So far the future looks bright for the use of 2-dimensional phosphorus in semiconductors instead of silicon. Semiconductors and their success effects our lives every day without people even realizing it. Semiconductors are in all of our electronic devices, from our smartphones to the computers in our cars. Their effectiveness is what keeps us connected in today’s technology dependent society. If phosphorus is the answer to fewer interruptions in our devices, then it will be welcomed with open arms because let’s be honest nothing is more upsetting than when your smartphone malfunctions.
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