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Identification and design principles of low hole effective mass p-type transparent conducting oxides.

Hautier G, Miglio A, Ceder G, Rignanese GM, Gonze X - Nat Commun (2013)

Bottom Line: The development of high-performance transparent conducting oxides is critical to many technologies from transparent electronics to solar cells.Here we conduct a high-throughput computational search on thousands of binary and ternary oxides and identify several highly promising compounds displaying exceptionally low hole effective masses (up to an order of magnitude lower than state-of-the-art p-type transparent conducting oxides), as well as wide band gaps.In addition to the discovery of specific compounds, the chemical rationalization of our findings opens new directions, beyond current Cu-based chemistries, for the design and development of future p-type transparent conducting oxides.

View Article: PubMed Central - PubMed

Affiliation: Institut de la matière condensée et des nanosciences (IMCN), European Theoretical Spectroscopy Facility (ETSF), Université Catholique de Louvain, Chemin des étoiles 8, bte L7.03.01, Louvain-la-Neuve 1348, Belgium. geoffroy.hautier@uclouvain.be

ABSTRACT
The development of high-performance transparent conducting oxides is critical to many technologies from transparent electronics to solar cells. Whereas n-type transparent conducting oxides are present in many devices, their p-type counterparts are not largely commercialized, as they exhibit much lower carrier mobilities due to the large hole effective masses of most oxides. Here we conduct a high-throughput computational search on thousands of binary and ternary oxides and identify several highly promising compounds displaying exceptionally low hole effective masses (up to an order of magnitude lower than state-of-the-art p-type transparent conducting oxides), as well as wide band gaps. In addition to the discovery of specific compounds, the chemical rationalization of our findings opens new directions, beyond current Cu-based chemistries, for the design and development of future p-type transparent conducting oxides.

No MeSH data available.


Related in: MedlinePlus

Vacancy formation energy versus Fermi energy.The panels indicate results for Sb4Cl2O5 (a) K2Sn2O3 (b) and K2Pb2O3 (c). The oxygen vacancy formation energy is indicated by a blue line. The cation vacancies are indicated by orange and purple lines. All defects are calculated in oxidizing conditions. The zero of Fermi energy is the valence band maximum.
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f3: Vacancy formation energy versus Fermi energy.The panels indicate results for Sb4Cl2O5 (a) K2Sn2O3 (b) and K2Pb2O3 (c). The oxygen vacancy formation energy is indicated by a blue line. The cation vacancies are indicated by orange and purple lines. All defects are calculated in oxidizing conditions. The zero of Fermi energy is the valence band maximum.

Mentions: For the remaining chemistries of greatest interest, we perform defect computations (see Methods), focusing on all the vacancy intrinsic defects as in Trimarchi et al.35Figure 3 shows the defect-formation energy as a function of the Fermi energy for Sb4Cl2O5, K2Sn2O3 and K2Pb2O3 in oxidizing conditions (most favourable for p-type behaviour). Figure 3a shows that Sb4Cl2O5 is not likely to be p-type doped. Indeed, when the Fermi energy is close enough to the valence band to generate holes, compensating defects (that is, oxygen and chlorine vacancies) will form spontaneously and act as hole killers. On the other hand, for K2Sn2O3 (Fig. 3b), the oxygen vacancy will not compensate hole formation. Moreover, the presence of a low-energy potassium vacancy can lead to intrinsic p-type behaviour for this material. This behaviour is similar to the defect energetics in known p-type oxides such as Cu2O (ref. 36), or CuAlO2 (ref. 37). K2Pb2O3 shows a similar behaviour (see Fig. 3c) as well as the other bcc phase of K2Sn2O3 (see Supplementary Fig. S23). These results demonstrate that all our most promising candidates (apart from Sb4Cl2O5) do not only combine low hole effective masses and wide band gap but have also defect energetics favouring p-type behaviour. The determination of the exact amount of hole carriers that those materials could be doped with (intrinsically or extrinsically) will require future experimental and theoretical work. Both high hole and low hole concentrations are of interest, depending on the application. In devices such as solar cells, where high hole conductivity is sought for, we typically look for high hole concentration TCOs. However, other devices such as transparent transistors typically require TCOs with lower hole concentrations38.


Identification and design principles of low hole effective mass p-type transparent conducting oxides.

Hautier G, Miglio A, Ceder G, Rignanese GM, Gonze X - Nat Commun (2013)

Vacancy formation energy versus Fermi energy.The panels indicate results for Sb4Cl2O5 (a) K2Sn2O3 (b) and K2Pb2O3 (c). The oxygen vacancy formation energy is indicated by a blue line. The cation vacancies are indicated by orange and purple lines. All defects are calculated in oxidizing conditions. The zero of Fermi energy is the valence band maximum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3753546&req=5

f3: Vacancy formation energy versus Fermi energy.The panels indicate results for Sb4Cl2O5 (a) K2Sn2O3 (b) and K2Pb2O3 (c). The oxygen vacancy formation energy is indicated by a blue line. The cation vacancies are indicated by orange and purple lines. All defects are calculated in oxidizing conditions. The zero of Fermi energy is the valence band maximum.
Mentions: For the remaining chemistries of greatest interest, we perform defect computations (see Methods), focusing on all the vacancy intrinsic defects as in Trimarchi et al.35Figure 3 shows the defect-formation energy as a function of the Fermi energy for Sb4Cl2O5, K2Sn2O3 and K2Pb2O3 in oxidizing conditions (most favourable for p-type behaviour). Figure 3a shows that Sb4Cl2O5 is not likely to be p-type doped. Indeed, when the Fermi energy is close enough to the valence band to generate holes, compensating defects (that is, oxygen and chlorine vacancies) will form spontaneously and act as hole killers. On the other hand, for K2Sn2O3 (Fig. 3b), the oxygen vacancy will not compensate hole formation. Moreover, the presence of a low-energy potassium vacancy can lead to intrinsic p-type behaviour for this material. This behaviour is similar to the defect energetics in known p-type oxides such as Cu2O (ref. 36), or CuAlO2 (ref. 37). K2Pb2O3 shows a similar behaviour (see Fig. 3c) as well as the other bcc phase of K2Sn2O3 (see Supplementary Fig. S23). These results demonstrate that all our most promising candidates (apart from Sb4Cl2O5) do not only combine low hole effective masses and wide band gap but have also defect energetics favouring p-type behaviour. The determination of the exact amount of hole carriers that those materials could be doped with (intrinsically or extrinsically) will require future experimental and theoretical work. Both high hole and low hole concentrations are of interest, depending on the application. In devices such as solar cells, where high hole conductivity is sought for, we typically look for high hole concentration TCOs. However, other devices such as transparent transistors typically require TCOs with lower hole concentrations38.

Bottom Line: The development of high-performance transparent conducting oxides is critical to many technologies from transparent electronics to solar cells.Here we conduct a high-throughput computational search on thousands of binary and ternary oxides and identify several highly promising compounds displaying exceptionally low hole effective masses (up to an order of magnitude lower than state-of-the-art p-type transparent conducting oxides), as well as wide band gaps.In addition to the discovery of specific compounds, the chemical rationalization of our findings opens new directions, beyond current Cu-based chemistries, for the design and development of future p-type transparent conducting oxides.

View Article: PubMed Central - PubMed

Affiliation: Institut de la matière condensée et des nanosciences (IMCN), European Theoretical Spectroscopy Facility (ETSF), Université Catholique de Louvain, Chemin des étoiles 8, bte L7.03.01, Louvain-la-Neuve 1348, Belgium. geoffroy.hautier@uclouvain.be

ABSTRACT
The development of high-performance transparent conducting oxides is critical to many technologies from transparent electronics to solar cells. Whereas n-type transparent conducting oxides are present in many devices, their p-type counterparts are not largely commercialized, as they exhibit much lower carrier mobilities due to the large hole effective masses of most oxides. Here we conduct a high-throughput computational search on thousands of binary and ternary oxides and identify several highly promising compounds displaying exceptionally low hole effective masses (up to an order of magnitude lower than state-of-the-art p-type transparent conducting oxides), as well as wide band gaps. In addition to the discovery of specific compounds, the chemical rationalization of our findings opens new directions, beyond current Cu-based chemistries, for the design and development of future p-type transparent conducting oxides.

No MeSH data available.


Related in: MedlinePlus