Energy transfer in argon atom – Surface interactions studied by Pt–SiO2–Si thin film chemoelectronic devices

• Gas induced cooling on a heated chemoelectronic device is studied.
• Energy transfer from the heated chemoelectronic device to the gas phase causes device currents.
• Device heating (during exothermic surface reactions) and device cooling (during subsequent energy transfer to reaction products) has to be taken into account.

The energy transferred from a heated platinum surface to an adjacent argon gas of several mbar pressure is studied. The cooling effects during accommodation of the argon atoms when colliding with the surface can be monitored by current changes in a chemoelectronic device, in this case consisting of silicon, silicon-oxide and platinum. A numerical heat flow model and the experimentally observed temperature dependence of the conduction in the device show that the observed signals are due to a cooling of the whole device. Temperature gradients and accompanying thermoelectric effects play only a minor role.