▎ 摘　　要

NOVELTY - Processing simple and controllable molecular evaporation comprise (i) placing molecule in sealed crucible, connecting inner chamber of crucible with vacuum cavity through the corrugated pipe sealing valve, and using molecular pump to pump cavity to super-high vacuum state, (ii) placing crucible in stainless steel cup filled with liquid nitrogen, completely placing crucible below liquid nitrogen liquid level, opening corrugated pipe sealing valve and observing current display number on molecular pump controller, and immediately closing corrugated pipe sealing valve, (iii) repeating operation two, keeping corrugated pipe sealing valve in completely open state for molecular pump for crucible internal molecular degassing and closing corrugated pipe sealing valve, and (iv) maintaining crucible temperature, placing clean surface crystal in vacuum cavity, and opening pipe sealing valve, when vacuum gauge connected with vacuum cavity begins to change, keeping loose tube sealing valve. USE - The method is useful for processing simple and controllable molecular evaporation, which is useful in the field of surface scientific research, and in the preparation of graphene of electrical device. ADVANTAGE - The method: is economical; solves the problems of small mass number, large saturated steam pressure, low evaporation temperature, and evaporated problem of high temperature easily deteriorated molecule under ultra-high vacuum condition; controls the operation by the bellows sealing valve, the entire evaporation process of the molecules can be controlled in time, the equipment is simple, and the operation is convenient; and prevents the molecular pump to the precursor molecule from crucible all pumping risk. A distance between the crucible containing the molecule and the vacuum cavity is cavity with a distance and the valve, so it can prevent some high temperature unstable molecule deterioration when the vacuum baking cavity some molecular. DETAILED DESCRIPTION - Processing simple and controllable molecular evaporation comprise (i) placing molecule in sealed crucible, connecting inner chamber of crucible with vacuum cavity through the corrugated pipe sealing valve, where corrugated pipe sealing valve is in closed state, and using molecular pump to pump cavity to super-high vacuum state, (ii) placing crucible in stainless steel cup filled with liquid nitrogen for 8-20 seconds, preferably 10 seconds, completely placing crucible below liquid nitrogen liquid level, opening corrugated pipe sealing valve and observing current display number on molecular pump controller, and immediately closing corrugated pipe sealing valve until vacuum degree in vacuum cavity reduced to ideal state, when current number is increased to 5 A, (iii) repeating operation two until corrugated pipe sealing valve is completely opened, and molecular pump controller current display number is lower than 5 A, keeping corrugated pipe sealing valve in completely open state for period of time for molecular pump for crucible internal molecular degassing and closing corrugated pipe sealing valve, and (iv) maintaining crucible temperature at liquid nitrogen cooling temperature or room temperature heating or high temperature heating, placing clean surface crystal in vacuum cavity the vacuum degree is less than or equal to 3x10-10 torr, and opening pipe sealing valve, when vacuum gauge connected with vacuum cavity begins to change, keeping loose tube sealing valve for 4-8 seconds, preferably 5 seconds after closing corrugated pipe sealing valve, where single crystal has surface large amount of crucible molecule.