SEGMENT REPORTING - Net losses (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
SEGMENT REPORTING
Revenue	$ 32		$ 40		$ 55	$ 40
Cost of revenue	28		32		29	32
Gross profit	4		8		26	8
Other operating income	279		236		530	438
Operating expenses
Research and development	2,426		1,158		3,923	2,434
General and administrative	2,360		1,844		4,369	3,206
(Gain) / loss on foreign currency transactions	(131)		19		(226)	32
Total operating expenses	4,655		3,021		8,066	5,672
Loss from operations	(4,372)		(2,777)		(7,510)	(5,226)
Total non-operating income / (expense)	1,973		(321)		2,952	432
Loss before income taxes	(2,399)		(3,098)		(4,558)	(4,794)
Income tax refund / (expense)	(1)		(1)		24	(1)
Net loss	(2,400)	$ (2,134)	(3,099)	$ (1,696)	$ (4,534)	$ (4,795)
Semiconductor materials segment
SEGMENT REPORTING
Revenue	32		40
Cost of revenue	28		32
Gross profit	4		8
Other operating income	279		236
Operating expenses
Research and development	2,426		1,158
General and administrative	2,360		1,844
(Gain) / loss on foreign currency transactions	(131)		19
Total operating expenses	4,655		3,021
Loss from operations	(4,372)		(2,777)
Total non-operating income / (expense)	1,973		(321)
Loss before income taxes	(2,399)		(3,098)
Income tax refund / (expense)	(1)		(1)
Net loss	$ (2,400)		$ (3,099)