Monitoring oxygen species in diamond hot-filament CVD by zircon dioxide sensors

Real-time monitoring of luminescent lifetime changes of PtOEP oxygen sensing film with LED/photodiode-based time-domain lifetime device

“…1,42 It is known the phosphorescence variation of PtOEP in the presence of O 2 is due to the collision quenching effect of O 2 molecules on the excited PtOEP molecules, thus the lifetime changes are directly coupled to the luminescent intensity changes; therefore, the most simple Stern-Volmer equation can Measured with the home-assembled optical fiber/flow cell system and the phosphorescence lifetime device (513 nm LED as excitation light source and the emission above 600 nm is used for the s monitoring). Note that the detection limit of the device is about 2 ms. be expressed as eqn (9), 1 where F 0 and s 0 are the initial luminescent intensity and lifetime in N 2 , F and s are the initial luminescent intensity and lifetime in the presence of O 2 , K D is the Stern-Volmer quenching constant and [Q] is the concentration of quenchers (herein it is O 2 ).…”

“…In this model, the dye molecules are also treated as two portions, but each portion has different O 2 accessibility, or different quenching constants. 42 Our O 2 quenching data, either recorded as intensity or lifetime profile, were fitted and it was found that the simple Stern-Volmer equation (eqn (9)) is enough to describe the quenching data with a linear plotting (Fig. 10).…”

“…However, these sensors are not suitable for much of the new O 2 analytical demands, due to the intrinsic drawbacks of these devices, such as slow response (up to several minutes to reach equilibrium), consumption of O 2 , bulky sensor configuration, or high operational temperature, etc. [9][10][11] New alternatives of luminescence O 2 sensors have emerged in recent years. [12][13][14] These sensors are attractive as they show faster response, do not consume O 2 and are not susceptible to electrical interference, e.g.…”

Long-lived emissive intra-ligand triplet excited states (3IL): next generation luminescent oxygen sensing scheme and a case study with red phosphorescent diimine Pt(ii) bis(acetylide) complexes containing ethynylated naphthalimide or pyrene subunits

“…However, they are not suitable for the new analytical demands due to the intrinsic drawbacks, such as high operational temperature, slow response, etc. [9][10][11] Quenched-luminescent O 2 sensing emerged in recent years. [12][13][14] These oxygen sensors are attractive since they are not O 2 consuming, have low power consumption, fast response and can be readily miniaturized, capable of in vivo detection, etc.…”

Growth of Nano Crystalline Diamond on Silicon Substrate Using Different Etching Gases by HFCVD

“…Various techniques were pursued by numerous researchers using plasma enhanced chemical vapor deposition (PECVD) [13][14][15][16][17][18][19], microwave plasma chemical vapor deposition (MWCVD) [20,21] and high pressure high temperature (HPHT) [22,23] methods for growing diamond films and diamond single crystals. The hot filament chemical vapor deposition (HFCVD) based deposition technique is one of the most common methods due to its low capital cost and allows the diamond deposition in a simple way, overcoming some of the limitations of the other more sophisticated chemical vapor deposition (CVD) techniques and there are several reports for growing nanocrystalline diamond by HFCVD system [12,[24][25][26][27][28][29]. In HFCVD, with the mixture of methane CH 4 and hydrogen H 2 gases, various species formations depend on many factors such as the temperature of the filament, system pressure, composition, and the flow rate of the incoming gas and the extent of the various chemical reactions on an the filament surface [25].…”